Anny Zúñiga — Photography
Pere Soto — Art Design
Copyright © 2026 Pere Soto Tejedor
ISBN: 9798190281477
Independently Published
Pere Soto — Art Design
Copyright © 2026 Pere Soto Tejedor
ISBN: 9798190281477
Independently Published
The language of harmony has never been static. Throughout the history of Western music, composers and performers have continually expanded the expressive possibilities of chordal structures, transforming what was once considered dissonance into an accepted element of musical vocabulary. The classification system presented in The Monster Chord Book should be understood within this historical continuum: not as a new harmonic theory, but as a systematic framework for organizing the vast harmonic language that has gradually evolved over the last three centuries.
The foundations of modern tonal harmony were established during the Baroque period, most notably through the work of the French composer and theorist Jean-Philippe Rameau. In his Traité de l’harmonie (1722), Rameau formalized the principles of tertian construction—the stacking of thirds to build chords—and introduced concepts such as chord roots, inversions, and harmonic function. These ideas became the structural basis of tonal music and influenced generations of composers from Johann Sebastian Bach, Joseph Haydn, Wolfgang Amadeus Mozart, and Ludwig van Beethoven to the Romantic masters of the nineteenth century.
As musical language evolved, composers increasingly challenged the limits of traditional tonal harmony. Franz Schubert expanded harmonic modulation into distant tonal regions, Frédéric Chopin enriched harmonic color through chromatic voice leading, Franz Liszt explored bold symmetrical structures, and Richard Wagner stretched functional harmony almost to its breaking point through prolonged tension and delayed resolution. Later, composers such as Claude Debussy and Maurice Ravel introduced modal colors, parallel harmonic movement, and sonorities whose expressive value often outweighed their traditional functional role. In the twentieth century, Igor Stravinsky, Béla Bartók, Alexander Scriabin, Olivier Messiaen, and Paul Hindemith each proposed new approaches to harmonic organization, demonstrating that harmony could continue to evolve without abandoning its structural foundations.
While classical music opened these new possibilities, jazz transformed many of them into an everyday musical language. Beginning in the early twentieth century, musicians systematically adopted seventh chords as the basic harmonic unit and incorporated upper extensions—9ths, 11ths, and 13ths—together with altered tensions such as ♭9, ♯9, ♯11, and ♭13. Figures including Duke Ellington, Art Tatum, Charlie Parker, Dizzy Gillespie, Thelonious Monk, Bud Powell, Bill Evans, John Coltrane, McCoy Tyner, Herbie Hancock, Wayne Shorter, and Chick Corea demonstrated an extraordinary capacity to combine harmonic sophistication with practical musical application. Their work established extended harmony not merely as an occasional color but as the normal vocabulary of modern improvisation and composition.
As jazz continued to develop through modal jazz, post-bop, fusion, and contemporary styles, harmonic language became even richer. Quartal harmony, upper-structure triads, slash chords, polychords, hybrid sonorities, and increasingly dense harmonic textures expanded the expressive palette available to composers and improvisers. Although these developments often moved beyond the traditional concepts of functional harmony, they generally remained rooted in the same fundamental principle of organizing pitch relationships into coherent harmonic structures.
Despite this remarkable evolution, no universally accepted system has emerged for classifying the enormous variety of modern chords. Equivalent sonorities are frequently labeled differently, chord symbols often vary from one publication to another, and the boundaries between chord families are not always clearly defined. This lack of consistency becomes particularly evident on the guitar, where multiple voicings can represent the same harmonic identity while different note omissions may preserve—or alter—that identity depending on the musical context.
The classification system developed in The Monster Chord Book seeks to address this challenge. Rather than replacing existing harmonic theory, it provides a logical and internally consistent method for organizing modern tertian harmony according to structural priorities, chord families, essential chord tones, extensions, alterations, and functional relationships. The objective is not to prescribe how harmony should be used, but to offer musicians a clear conceptual map capable of navigating one of the richest harmonic vocabularies ever developed.
In this sense, this work represents both a synthesis of nearly three centuries of harmonic evolution and a practical framework for understanding, classifying, and exploring the immense harmonic possibilities available to today's guitarist, composer, arranger, and improviser.
The guitar is often approached through shapes.
Most players learn chords as visual patterns, memorizing positions and fingerings that can be moved across the fretboard. While this approach is practical, it frequently obscures a deeper understanding of the instrument: every chord is ultimately a collection of intervals, tensions and relationships that exist independently of any particular shape.
Rather than presenting a limited selection of commonly used voicings, this book documents an extensive range of harmonic possibilities organized by root, chord quality and melodic placement. Each voicing has been conceived with a specific top note, allowing the reader to understand not only the harmonic structure of the chord but also its melodic implications. In this way, the material serves equally well as a reference for harmony, arranging, improvisation and chord melody.
This work aims to reveal the underlying harmonic relationships that connect the entire fretboard, moving beyond the simple memorization of isolated chord shapes.
A major seventh chord remains a major seventh chord regardless of its position on the instrument. A dominant chord retains its function regardless of its inversion.
By studying these structures systematically, the guitarist begins to perceive the fretboard not as a collection of isolated patterns, but as an interconnected harmonic landscape.
This book is intended for students, educators, arrangers, composers and professional performers who wish to deepen their understanding of harmonic language. It may be used as a reference work, a study guide, a source of compositional ideas or simply as a map of the guitar’s harmonic possibilities.
The pages that follow are an invitation to explore the guitar beyond familiar shapes and routines. My hope is that this work helps readers discover new connections, new sounds and, above all, a deeper understanding of the harmonic possibilities hidden within the instrument.
A complete catalog of chord structures across the guitar neck, covering multiple positions, inversions and melodic placements.
Each chord is presented as an intervallic structure rather than a mere fingering pattern, helping the player understand its internal construction and harmonic function.
Because every voicing is organized around a defined top note, the material can be used directly for chord melody arrangements, accompaniment and melodic harmonization.
Designed for study, composition, arranging and performance, this volume provides a comprehensive collection of guitar voicings organized within a coherent harmonic system.
The Monster Chord Book is the first volume of a long-term editorial project whose objective is to create a complete harmonic encyclopedia of the guitar.
Rather than presenting a selection of commonly used chord shapes, the encyclopedia systematically documents every chord admitted by the harmonic classification system developed in this work. Each volume explores a specific melodic position on the instrument, allowing every voicing to be studied within a clear and consistent organizational framework.
The complete collection is organized according to the melodic note on the first, second, and third strings. Each string is divided into twelve fret-based volumes, making it possible to examine every position independently while preserving a unified theoretical structure throughout the entire series.
When completed, the encyclopedia is expected to contain more than 40,000 guitar chord voicings in standard tuning. Every volume follows the same analytical methodology, harmonic nomenclature, and classification principles, ensuring complete consistency across the collection.
This volume is the first step in that project, covering all chord structures whose melodic note is located on the first string, open position (fret 0).
The following notes explain the editorial conventions and practical decisions adopted throughout this volume. They are intended to help the reader interpret the chord symbols, understand the analytical approach, and navigate the collection consistently.
Equivalent chord symbols may appear interchangeably throughout the book (e.g., Em7♭5 / Eø7, maj7 / Δ7). Likewise, enharmonic spellings are occasionally adapted for clarity and practical readability. Musical function and theoretical consistency always take precedence over orthographic preference.
Voicings requiring tapping are indicated by notes enclosed in parentheses, identifying the pitches to be played by the picking hand. In technically demanding structures, players are encouraged to adopt the fingering solution that best suits their own technique.
The theoretical analyses presented in Chapter I (Root E) apply equally to all subsequent chapters. Although the root changes from chapter to chapter, the intervallic structure, harmonic function, and classification principles remain identical. To avoid unnecessary repetition, the complete harmonic analysis is presented only once, while the remaining chapters focus on the corresponding collections of chord voicings and inversions.
The following naming conventions and editorial decisions are applied consistently throughout the encyclopedia.
The sixth (6) is treated as a structural chord tone in sixth and sixth/ninth chords. The thirteenth (13) is regarded as an upper extension of seventh chords. When both spellings are theoretically possible, the harmonic context and chord family determine the preferred notation.
In dominant and half-diminished chords, the diminished fifth (♭5) is generally preferred because it represents a structural alteration of the chord. The ♯11 spelling is reserved for major and Lydian-dominant sonorities, where the raised fourth functions as a color extension rather than as a replacement for the fifth.
The augmented fifth (♯5) is used whenever it forms part of the chord’s structural identity (e.g., maj7♯5, 7♯5). The ♭13 spelling is preferred when the same pitch functions as an upper extension over a preserved perfect or diminished fifth.
A sus4 chord replaces the third with the fourth. An add11 chord adds the eleventh while retaining the third. The plain 11 designation is reserved for extended chords in which the third is present and the eleventh functions as a genuine extension.
Although uncommon, major-seventh chords containing a flattened ninth (♭9) are admitted when the altered ninth functions as a deliberate color tone. Within this system, these structures remain members of the major-seventh family rather than being reclassified as altered dominant chords.
When the physical limitations of the guitar prevent all chord tones from being performed simultaneously, omitted notes are explicitly indicated. As a general principle, priority is given to the tones that define the harmonic identity of the chord and to any explicitly requested extensions or alterations. Depending on the harmonic context, the root or the fifth are the tones most commonly omitted.
The chord symbols and formulas presented in this book describe complete harmonic structures. These formulas represent the theoretical collection of intervals that define each chord, regardless of the practical limitations of any specific instrument.
However, the guitar is a physically limited instrument. Unlike the piano, which can often perform large harmonic structures with all chord tones present, the guitarist must frequently make choices about which notes to include and which notes to omit. As chord complexity increases—especially in chords containing 9ths, 11ths, 13ths, and altered extensions—it becomes increasingly difficult, and often impossible, to perform every chord tone simultaneously within a practical fingering.
For this reason, many voicings in this book contain omitted notes. These omissions are always indicated and do not imply an error in the chord formula. The chord symbol refers to the complete theoretical structure, while the voicing represents one possible guitar realization of that structure.
In many musical situations, certain notes are more important than others. The 3rd and 7th often define the chord quality, while characteristic tensions such as #11, b9, #9, or b13 may contribute more strongly to the harmonic color than the root or the 5th. Consequently, some voicings may omit the root, the 5th, or even an extension explicitly named in the chord symbol in order to preserve a playable and musically meaningful guitar position.
The harmonic identity of a voicing also depends on musical context. A voicing played in isolation may suggest several possible interpretations. Within an ensemble, however, the presence of a bass player or other accompanying instruments often supplies the missing harmonic information, allowing the complete chord structure to be perceived even when certain chord tones are absent from the guitar voicing itself.
Therefore, this book distinguishes between two related but different concepts:
Theoretical Principles Governing the Chord Collection
This is not another guitar chord dictionary.
It is a systematic harmonic classification developed specifically for the modern guitarist, deeply rooted in the rich harmonic language of jazz and extended to contemporary music.
Building upon the foundational principles of tertian harmony first formalized by Jean-Philippe Rameau in the 18th century, and later expanded through the innovations of jazz harmony in the 20th and 21st centuries, this system organizes chords into coherent families defined by their structural tones, harmonic function, and permitted extensions.
Its purpose is to establish a complete and consistent classification of theoretical chord structures and their application to the guitar. The collection is based on harmonic logic rather than on traditional chord vocabulary or conventional guitar voicings. It utilizes formal chord nomenclature to ensure clarity, with all numeric extensions following standard musical alteration conventions (♭9, ♯11, ♭13, etc.).
This framework identifies and organizes every chord admitted by a logically consistent harmonic system. Each chord belongs to a specific family, preserving its identity and function. When the physical limitations of the six-string guitar prevent the full realization of a complete theoretical chord, omitted notes are explicitly indicated. The theoretical identity of the chord always takes precedence over its practical realization.
This work does not attempt to decide which chords musicians should use. Its purpose is to define, classify, and organize the harmonic structures that belong to a coherent theoretical system, leaving artistic judgment entirely to the musician.
This collection serves as a bridge between classical harmonic theory and the flexible, expressive demands of jazz improvisation, arranging, and composition — offering guitarists a clear, rigorous, and comprehensive map of the harmonic universe.
Every chord included in this collection satisfies three fundamental requirements:
If the addition or alteration of a note changes the identity of the chord, the result belongs to a different chord family.
Principle 1: Dual Priority. Chord classification and chord realization obey different priority systems. Theoretical priority determines the harmonic identity of the chord and is based on its structural tones. Performance priority determines which notes should be preserved when the complete chord cannot be performed. In this case, explicitly requested tensions and alterations become the highest priority, followed by the characteristic chord tones.
Principle 2: Identity Priority. Structural tones define the identity of every chord. Chord identity always has priority over theoretical possibilities. Theoretically possible sonorities are excluded whenever they contradict the identity of a chord family.
Principle 3: Functional Preservation. The harmonic function of each chord family must be preserved. Extensions that transform the harmonic role of a chord are intentionally excluded.
Principle 4: Instrumental Integrity. The guitar realization never modifies the theoretical definition of a chord. Because the guitar has physical limitations, when necessary, omitted notes are indicated to ensure the theoretical chord remains unchanged.
Principle 5: Logical Admissibility. A chord is admitted into this system not because it is common, beautiful, or stylistically accepted, but because it satisfies the structural and functional principles that govern the classification. Consequently, aesthetic value and practical usefulness remain matters of artistic choice rather than theoretical validity.
Principle 6: Harmonic Guideline — Maj7 Extensions and Alterations. Rule: Avoid combining a major 7th (maj7) quality with a flat 13th (b13).
Exception — Altered Major 7th Families (maj7#5 / maj7b5): This restriction does not apply to major 7th chords with altered fifths (maj7#5 or maj7b5). Because these structures already embrace an inherently altered harmonic framework—where the raised or lowered fifth is a foundational part of the chord’s color (such as the Lydian #5 system)—the incorporation of related tensions functions as an organic extension of their specialized character, rather than an unwanted cluster clash.
The entire classification system in this encyclopedia can be summarized in a single tree that starts from harmony itself and branches into the families and extensions described throughout this chapter:
From Harmony to Timbre. As harmonic density increases through the accumulation of extensions and added tones, functional harmony gradually dissolves. At its extreme, it gives rise to tone clusters — dense chromatic aggregates where individual chord identities blur into a unified sonic mass. Clusters represent the natural evolution of the system: no longer chords in the traditional sense, but complex timbral structures born from harmonic logic itself.
Each chord family is defined by a set of structural tones. These tones establish the harmonic identity of the chord and take priority over all other considerations.
Chords in this classification system are organized into two primary categories based on their construction and harmonic nature: Tertian Chords and Added-Tone Chords.
Tertian Chords are built by stacking thirds above the root, following traditional Western harmonic practice. These chords generally include a seventh (or sixth) and form the core of the system’s functional harmony.
Added-Tone Chords, by contrast, consist of a major or minor triad to which one or more non-tertian tones are added directly, without introducing a seventh. These chords expand the coloristic possibilities of the basic triad while preserving its fundamental harmonic identity.
This clear separation allows the system to distinguish between chords with strong functional implications (tertian) and those that function primarily as enriched triads with added color.
These chords are formed by adding one or more non-structural tones directly to a major or minor triad without introducing a seventh.
Within the classical tradition, these elements are often classified as “non-chord tones” (notas extrañas), typically functioning as passing notes, neighbor tones, or suspensions that require resolution. However, within this classification system, these tones are elevated to stable harmonic components.
Rather than functioning as transient melodic events, they are treated as coloristic additions that expand the sonic palette of the triad while maintaining its fundamental identity. By integrating these “extra” tones as permanent structures, the system formalizes what was traditionally considered decorative, transforming them into legitimate harmonic extensions that define the chord’s personality without the functional baggage of seventh-chord verticality.
Examples: add9, add11, add♯11, add♭9, add♯9, add13, add♭6, add♯5.
The presence of a seventh immediately transfers the chord to the corresponding tertian family.
Extensions are excluded whenever they duplicate an existing structural tone through enharmonic equivalence.
These exclusions preserve both notation and harmonic identity.
Some extensions are excluded because they alter the harmonic function of the chord.
Each family has its own extension rules. Current families include:
Each family defines: structural tones, permitted extensions, forbidden extensions, functional restrictions, and enharmonic restrictions.
In a minor 7th chord (m7), one may include a ♭9 or an add♭9 as a color tone. However, once a ♭9 is introduced, the chord reaches a density threshold. To preserve the modal essence of the m7, only natural 11 and natural 13 extensions are permitted.
Any inclusion of altered tensions—specifically ♯11 or ♭13—in combination with a ♭9 is forbidden, as these additions dissolve the harmonic identity of the m7 and effectively transform the structure into a polychord.
There is a distinct difference between using an isolated color tone and constructing an entire complex block of tensions. The latter effectively results in a polychord. For example, an Eb-7(♭9,11,13) maintains a functional link to the m7, whereas an Eb-7(♭9,♯11,♭13) shifts the chord toward a completely different harmonic essence.
In summary: When a ♭9 is present, the chord must remain within the “natural” extension sphere. The use of altered tensions (♯11, ♭13) in this context is prohibited, as they break the character of the original chord.
Unlike the restricted minor 7th family, diminished chords (dim7) possess a unique structural stability derived from their symmetrical interval construction. This strength—often explored by artists such as Dave Liebman and Richie Beirach—allows the chord to function as a vessel for various extensions, including the major 7th (Δ7), without losing its “mysterious” and balanced identity.
However, a strict limitation applies: extensions must not be applied simultaneously.
The rationale for this law is twofold:
In summary: Permitted — individual extensions (9, ♭9, 13, ♭13, Δ7) added as discrete coloristic choices. Forbidden — simultaneous layering of multiple altered extensions. Goal — to maintain the diminished chord’s unique duality, preserving both its structural symmetry and its viability as a functional dominant substitute.
Colour key: Green =Permitted · Blue =Structural · Yellow =Added-Tone only · Orange =Context-dependent.
| Chord Family | 9 | ♭9 | ♯9 | 11 | ♯11 | 13 | ♭13 |
|---|---|---|---|---|---|---|---|
| maj7 | ✓ | ✓ | ✓ | A | ✓ | ✓ | ✓ |
| maj7♭5 | ✓ | ✓ | ✓ | A | ✓ | ✓ | ✓ |
| maj7♯5 | ✓ | ✓ | ✓ | A | ✓ | ✓ | E |
| 7 | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| 7♭5 | ✓ | ✓ | ✓ | ✓ | E | ✓ | ✓ |
| 7♯5 | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | E |
| mMaj7 | ✓ | ✓ | E | ✓ | F | ✓ | ✓ |
| m7 | ✓ | ✓ | E | ✓ | F | ✓ | ✓ |
| m7♭5 | ✓ | ✓ | E | ✓ | E | ✓ | ✓ |
| dim7 | ✓ | ✓ | E | S | E | E | ✓ |
| 7sus4 | ✓ | ✓ | F | R | F | ✓ | ✓ |
| m7sus4 | ✓ | ✓ | E | R | F | ✓ | ✓ |
| 6 | ✓ | ✓ | T | A | ✓ | — | F |
| m6 | ✓ | ✓ | E | ✓ | F | — | F |
| 6/9 | — | T | T | A | ✓ | — | F |
| m6/9 | — | T | E | ✓ | F | — | F |
| Code | Meaning |
|---|---|
| ✓ | Permitted |
| — | Structural tone |
| A | Added-Tone only |
| E | Enharmonic duplication |
| F | Functional preservation |
| R | Structural redundancy |
| S | Structural stability |
| T | Tensional hierarchy |
Major and minor triads are closed harmonic structures. They do not admit extensions. Any additional note creates a new harmonic family.
Examples: C → Major Triad · Cmaj7 → Major Seventh · C6 → Sixth Chord · Cadd9 → Added-Tone Chord.
Altered dominant chords constitute a special family within the system. Due to the large number of possible simultaneous alterations, the generic symbol 7alt is adopted to represent this category.
The 7alt chord includes all the characteristic extensions and alterations of the altered dominant. This encompasses:
Core Rule: The symbol 7alt represents any valid combination of these alterations, allowing several of them to coexist simultaneously within the same chord. Examples: C7♭9, C7♯9, C7♭5♯9, C7♯5♭9, C7♭5♯5♭9♯11, C7alt (generic representation that encompasses all the above combinations).
This approach avoids exhaustive and redundant individual listings while preserving the theoretical completeness of the system.
Important Note on Enharmonic Spelling: Although ♯11 is enharmonically equivalent to ♭5 and ♭13 to ♯5, both notations are acceptable depending on harmonic context and the preference of the composer or arranger. The system prioritizes functional clarity over strict simplification.
This family retains a strong dominant function (strong tendency to resolve to the tonic), but its highly tense sonority makes it particularly useful in modern jazz, fusion, and contemporary music.
In this harmonic classification system, we have deliberately excluded polychords.
Although polychords are a powerful and fascinating tool within contemporary harmony and modern composition, they represent a distinct harmonic system that falls beyond the scope and purpose of this book.
This work focuses on chords with a clear and unique harmonic identity, organized according to functional and logical principles that facilitate their practical application on the guitar. Polychords, by their very nature, involve the superposition of two or more independent harmonic structures, bringing them closer to the realm of orchestration, advanced arranging, and harmonic experimentation rather than everyday guitar practice.
Therefore, we believe polychords deserve a dedicated and in-depth treatment in a future volume focused on extended harmonic structures and advanced techniques of modern harmony.
Here we remain faithful to our main objective: to provide a clear, rigorous, and practical framework for guitarists seeking to master the universe of chords with well-defined identities.
Within this harmonic classification system, chords with a high degree of density—particularly those containing multiple simultaneous extensions and alterations—can produce sonorities that suggest the superposition of two or more independent triadic structures. These are referred to as hybrid chords.
Although they do not qualify as true polychords (since they maintain a primary root and a clear functional identity), their vertical complexity often creates effects similar to layered triads. For example:
This characteristic is especially valuable in modern jazz, fusion, and contemporary composition, allowing the guitarist to exploit these ambiguous sonorities for color and depth while remaining within the functional logic of the system.
Hybrid chords represent the transitional zone between traditional extended harmony and the more open structures of 20th- and 21st-century music, always preserving the priority of the chord’s primary harmonic identity as defined by its structural tones.
These examples perfectly illustrate how dense extended chords naturally produce hybrid / polychord-like effects while still maintaining a clear primary root and function within the system.
As we aggregate extensions—incorporating not only distant tensions but also stable “added-tones”—the harmonic density increases to a point where the traditional functional relationship between notes begins to dissolve. When a chord contains a high number of unique pitches, the human ear shifts its perception from pitch identification to timbral analysis.
At this saturation point, we approach the boundary of tone clusters: dense, chromatical groupings where individual harmonic identities are subordinated to a unified sonorous mass. In this “clusternian” universe, the guitar ceases to function as a traditional harmonic tool and transitions into a percussive and timbral instrument.
This transformation aligns with Arnold Schoenberg’s early 20th-century definitions, where the “color” (Klangfarben) of a sonority becomes as structurally significant as its melodic role. Composers of the 20th century, such as Olivier Messiaen (with his modes of limited transposition and dense resonance) and György Ligeti (in his exploration of micropolyphony and sound masses), utilized these “overloaded” harmonies not to create tension-and-release cycles, but to occupy sonic space.
In this system, the “sphere of the 11ths and 13ths” represents the frontier of functional harmony. When we push these chords toward maximal density:
This formalizes the practice of modern arranging and composition, where the guitar is often used to create a “thick” sonic environment—an aesthetic choice that prioritizes the resonance of the instrument over the resolution of the notes.
Because the guitar has only six strings and limited physical possibilities, many theoretical chord structures cannot be performed in their entirety. Whenever one or more notes are omitted, the omitted tones are explicitly identified. The theoretical chord always remains unchanged.
To expand the expressive possibilities and natural resonance of the instrument, an exception to the voicing height limitation is established when utilizing specific open-string notes.
Throughout this encyclopedia, open 6th-string root doublings have been intentionally omitted when they occur two octaves below the main harmonic structure. Within the context of guitar voicings, such a distant duplication contributes little to the harmonic identity of the chord while adding considerable low-frequency resonance.
Rather than reinforcing the chord’s defining tensions, the open-string bass tends to dominate the overall sonority, reducing the perceived clarity, balance, and transparency of altered structures. For this reason, priority has been given to voicings that present the harmonic information as clearly and efficiently as possible.
This should not be interpreted as a harmonic prohibition. It is simply an editorial criterion adopted throughout this encyclopedia for the guitar.
— Voicing intentionally excluded —
Every chord in this collection is generated according to the same logical procedure:
The following analysis is presented only once, using the root E as reference. The same intervallic structures, functions and principles apply to every subsequent chapter, regardless of the tonal center.
Fully diminished chords form a symmetrical harmonic system. Because a diminished seventh chord repeats every minor third, each voicing represents four enharmonic roots:
Edim7 = Gdim7 = Bbdim7 = C#dim7
Permitted individual extensions include 9, b9, b13 and Δ7. Simultaneous layering of multiple altered extensions is forbidden (see The Diminished Symmetry Law).
The 7alt chord represents the maximum expression of tension within the dominant family. It combines multiple altered extensions simultaneously — most commonly b9 / #9 together with b5 / #5 — generating the characteristic sound of the Altered Scale (Super Locrian mode).
Due to the extreme intervallic density, many theoretical combinations of double alterations become physically impractical on the guitar when the melodic note is fixed on the first string (fret 0). For this reason, not every theoretical combination has been included as a separate heading. The book prioritizes voicings that maintain musical coherence, playability and voice-leading clarity.
The voicings presented under E7b5, E7#5, E7(b9), E7(#9) and their extensions already cover the vast majority of practical applications of the altered dominant sound.
| Role of E (Fret 0) | Harmonic Context | Main Function |
|---|---|---|
| Root | Chapter I | Stability, chord root |
| Major 3rd | Chapter IX (C) | “Major” quality, tonal definition |
| Minor 3rd / #9 | Chapter X (C#) | Minor stability or blues/jazz tension |
| 4th / 11th | Chapter VIII (B) | Tonal “deactivation”, suspension, Jazz-Fusion |
| Perfect 5th | Various chapters | Point of rest, diatonic balance |
| b5 / #11 | Chapter VII (Bb) | Instability, Lydian color, maximum tension |
| 6th / 13th | Chapter IV (G) | Harmonic color, expansion, melodic richness |
| Major 7th | Chapter I | Leading tone, diatonic definition |
| Minor 7th | Various chapters | Dominant function, movement toward resolution |
| 9th / 2nd | Chapter XI (D) | Tonal opening, elimination of triad harshness |
| #9 / b2 | Chapter XII (Eb) | Maximum friction, harmonic kinetic energy |
This collection is intended to provide a complete theoretical classification of every chord admitted by this harmonic system. It is therefore a systematic harmonic language rather than a simple collection of guitar chord diagrams.
Every chord included in the collection exists because it satisfies the principles defined in this Harmonic Classification System.
This work is not intended to prescribe compositional practice, stylistic preferences, or aesthetic judgment. Its objective is to establish a logically consistent harmonic classification that organizes every chord admitted by the principles of this system.
The inclusion of a chord does not imply that it is common, easy to perform, or aesthetically preferable. Likewise, the exclusion of a theoretically conceivable chord does not suggest that it cannot be used creatively; it simply indicates that it falls outside the logical boundaries established by this classification.
The purpose of this work is therefore descriptive and organizational rather than prescriptive. It provides a coherent map of the harmonic universe, allowing musicians to understand, locate, compare, and explore chord structures within a unified theoretical framework.
Musical value ultimately depends on artistic context, interpretation, and intention. This system merely defines the structural language through which those possibilities can be understood.
Pere Soto is a composer, guitarist, and educator whose career is defined by an uncompromising pursuit of harmonic depth and stylistic eclecticism. With a trajectory spanning over two decades of international performance and creation, Soto has established himself as a bridge between the raw, instinctive language of jazz and the formal precision of classical composition.
Soto’s creative output is as vast as it is diverse. His catalogue features more than 200 compositions, ranging from solo guitar works to ambitious scores for chamber ensembles and symphonic orchestra. His classical works for the guitar are recognized for their structural complexity and a unique ability to weave contemporary harmonic concepts into the classical tradition.
As a performer, Pere Soto is a master of the guitar’s “vertical” possibilities. His deep knowledge of the instrument’s fretboard is the foundation of his work. He does not merely play the guitar; he dissects it. This intimate relationship with the fretboard has led him to develop a unique methodology that prioritizes functional harmony and voice-leading.
Pere Soto has dedicated years of research to documenting the harmonic potential of the guitar. His series of books — including this Monster Chord Book — serves as the definitive reference for guitarists seeking to master the architecture of chord melody. These works are not traditional manuals; they are rigorous analytical encyclopedias born from a musician’s need to organize the complexities of the neck into a coherent, accessible system.
By combining the rigor of a musicologist with the soul of an active performer, Pere Soto’s literature is an essential resource for any musician aiming to navigate the fretboard with total freedom and authority.