Guitar and harmony glossary

100 terms explained simply, with examples to play on the fretboard: intervals, chords, scales, harmony, rhythm and guitar technique.

Every entry gives a clear definition, how to play the idea on the guitar, a concrete example, common mistakes and the workshop tools to practise it.

#

12-bar blues: The 12-bar blues is a twelve-bar chord progression built on the I, IV and V chords of a key, usually played as dominant sevenths, such as A7, D7 and E7 in A.

A

Add9 chord: An add9 chord is a major or minor triad with the ninth added and no seventh: Cadd9 is spelled C, E, G and D.
Aeolian mode: The Aeolian mode is the sixth mode of the major scale and the same thing as the natural minor scale: 1 2 b3 4 5 b6 b7, the default dark minor sound.
Altered dominant chord: An altered dominant chord is a dominant seventh chord whose fifth and/or ninth are raised or lowered (♭9, #9, ♭5, #5), which increases its tension before it resolves.
Arpeggio: An arpeggio is a chord played one note at a time instead of strummed together: you sound its root, third, fifth (and seventh) individually, ascending or descending.
Augmented chord: An augmented chord is a triad made of two stacked major thirds: a root, a major third and an augmented fifth, such as C E G♯ for C+.

B

Bar (measure): A bar, or measure, is a unit of time that groups a fixed number of beats, set by the time signature and marked off on the page by vertical bar lines.
Barre chord: A barre chord is a chord where the index finger presses several strings at the same fret like a movable nut, so an open chord shape can be moved anywhere on the neck.
Blues scale: The blues scale is the minor pentatonic plus the flat fifth, or blue note: 1 ♭3 4 ♭5 5 ♭7, which gives A C D E♭ E G in the key of A.

C

Cadence: A cadence is the chord move that ends a musical phrase and punctuates it: conclusive like V-I, open like a stop on V, or surprising like V-vi.
CAGED system: The CAGED system links the five open chord shapes C, A, G, E and D so you can play the same major chord in five places on the neck, always in that order.
Capo: A capo is a clamp that presses all the strings at one fret; it acts as a new nut and raises everything you play by one semitone per fret.
Chord: A chord is a group of at least three different notes played together, built by stacking thirds on a root: C, E and G form a C major chord.
Chord inversion: A chord inversion is a chord whose lowest note is not the root: the third in the bass (first inversion), the fifth (second inversion) or the seventh (third inversion).
Chord progression: A chord progression is an ordered sequence of chords that forms the harmonic backbone of a piece, written with chord names (C G Am F) or Roman numerals (I-V-vi-IV).
Chord tones: Chord tones are the notes that make up a chord: root, third and fifth, plus the seventh in a seventh chord. They are the safest landing points for a melody or solo.
Chromatic scale: The chromatic scale is the sequence of all twelve notes in an octave, each a half step apart; on guitar, it means playing every fret one after another.
Circle of fifths: The circle of fifths arranges the twelve major keys (and their relative minors) a perfect fifth apart: each step adds one sharp one way and one flat the other way.
Consonance and dissonance: Consonance describes intervals and chords heard as stable and restful; dissonance describes those that create tension and ask for resolution, like the tritone in G7 moving to C.

D

DADGAD tuning: DADGAD is a guitar tuning (D A D G A D, low to high) whose open strings form a Dsus4 chord, widely used in Celtic and acoustic folk music.
Diatonic chords: Diatonic chords are the seven chords built only from the notes of a scale by stacking thirds on each degree, such as C, Dm, Em, F, G, Am and Bdim in C major.
Diminished chord: A diminished chord is a triad made of two stacked minor thirds: a root, a minor third and a diminished fifth, such as B D F for Bdim.
Diminished scale: The diminished scale is a symmetrical eight-note scale that alternates half steps and whole steps, used over 7♭9 dominant chords and diminished seventh chords.
Diminished seventh chord: A diminished seventh chord (dim7) stacks three minor thirds: 1 ♭3 ♭5 ♭♭7, as in Bdim7 = B D F A♭. It is symmetrical and repeats every 3 frets.
Dominant: The dominant is the fifth degree of a key and the chord built on it (V or V7), whose tension pulls back to the tonic, like G or G7 resolving to C in C major.
Dominant seventh chord: A dominant seventh chord is a major triad with a minor seventh on top (1 3 5 ♭7), such as G7 = G B D F, and it pulls strongly toward the tonic.
Dorian mode: The Dorian mode is the second mode of the major scale, with the formula 1 2 ♭3 4 5 6 ♭7: a minor mode with a major sixth that sounds brighter than natural minor.
Drop 2 voicing: A drop 2 voicing is built by taking a four-note chord in close position and dropping its second-highest note down an octave.
Drop D tuning: Drop D is a guitar tuning where only the 6th string is lowered a whole step, from E to D: D A D G B E, giving a deeper bass and one-finger power chords.

E

Enharmonic equivalent: Enharmonic equivalents are two different names for the same pitch, like F# and G♭: on the guitar they are the same fret, but the correct name depends on the key and the chord.
Extended chords (9, 11, 13): An extended chord continues a seventh chord by stacking thirds beyond the seventh: the ninth, eleventh and thirteenth, as in C9, Am11 or G13.

F

Fingerpicking: Fingerpicking means plucking guitar strings with your fingers, the thumb playing the bass strings while the index, middle and ring fingers play the treble strings.
Fret: A fret is a metal strip across the guitar neck; pressing a string just behind it shortens the string, and each fret raises the pitch by one semitone.
Fretboard: The fretboard is the front of the guitar neck where you press the strings; its frets divide it into semitones and hold every note you can play on six strings.

G

Guide tones: Guide tones are the third and seventh of a chord: they define its quality (major, minor or dominant) and connect the chords of a progression with small, smooth moves.

H

Half-diminished chord (m7♭5): A half-diminished chord (m7♭5 or ø) is a diminished triad with a minor seventh added: Bm7♭5 = B D F A. It sets up the dominant in minor keys.
Harmonic minor scale: The harmonic minor scale is natural minor with a raised seventh (1 2 ♭3 4 5 ♭6 7), which creates a leading tone and turns the five chord into a major dominant.

I

I-V-vi-IV progression: The I-V-vi-IV progression strings together the chords on degrees 1, 5, 6 and 4 of a major key, for example C G Am F in C, the backbone of thousands of pop songs.
ii-V-I progression: The ii-V-I is the progression of chords built on degrees 2, 5 and 1 of a key, such as Dm7 G7 Cmaj7 in C major, and it is the basic cadence of jazz.
Interval: An interval is the distance between two notes, named by a number (third, fifth) and a quality (major, minor, perfect): from C to E is a major third.
Ionian mode: The Ionian mode is the first mode of the major scale, with the formula 1 2 3 4 5 6 7: it is the major scale itself, seen as one of the seven modes.

K

Key: A key is the home base of a piece of music: a central note (the tonic), the major or minor scale built on it and the family of chords that scale produces.
Key signature: A key signature is the group of sharps or flats written at the start of every staff: it tells you which notes are altered throughout the piece, and so points to its key.

L

Locrian mode: The Locrian mode is the seventh mode of the major scale: 1 b2 b3 4 b5 b6 b7. Its flat fifth makes it the unstable scale of m7b5 chords.
Lydian mode: The Lydian mode is the fourth mode of the major scale: a major scale with a raised fourth (#4), which gives it a bright, floating, unresolved sound.

M

Major chord: A major chord is a triad made of a root, a major third (4 semitones up) and a perfect fifth (7 semitones up), such as C E G for C major.
Major pentatonic scale: The major pentatonic scale is a five-note scale, 1 2 3 5 6 (A B C# E F# in A), with a bright sound used in country, pop, rock and major blues.
Major scale: The major scale is a seven-note scale built on the pattern whole, whole, half, whole, whole, whole, half step: C major gives C D E F G A B.
Major seventh chord: A major seventh chord (maj7) is a major triad with a major seventh added, a semitone below the octave: Cmaj7 = C E G B.
Major third: A major third is the interval of four semitones, as from C to E: it is what makes a chord major, and on the guitar it spans four frets on one string.
Melodic minor scale: The melodic minor scale is a minor scale with a major sixth and major seventh (1 2 ♭3 4 5 6 7), and its modes are central to jazz improvisation.
Metronome: A metronome is a device that plays a steady click at a chosen tempo, measured in BPM, so you can play in time and build speed in a controlled way.
Minor chord: A minor chord is a triad made of a root, a minor third (3 semitones up) and a perfect fifth (7 semitones up), such as A C E for A minor.
Minor pentatonic scale: The minor pentatonic scale is a five-note scale, 1 ♭3 4 5 ♭7 (A C D E G in A), and the core soloing scale of rock and blues guitar.
Minor seventh chord: A minor seventh chord (m7) is a minor triad with a minor seventh added: Am7 = A C E G. It is the chord found on degrees ii, iii and vi of a major key.
Minor third: A minor third is the interval of three semitones, as from A to C: it gives minor chords their darker colour and spans three frets on one guitar string.
Mixolydian mode: The Mixolydian mode is the fifth mode of the major scale: a major scale with a flat seventh (b7), the natural sound of a dominant seventh chord.
Modal interchange (borrowed chords): Modal interchange means using chords borrowed from a parallel mode with the same tonic, such as Fm, A♭ or B♭ taken from C minor in a song in C major.
Modes: Modes are the seven scales you get by playing the major scale from each of its degrees: Ionian, Dorian, Phrygian, Lydian, Mixolydian, Aeolian and Locrian.
Modulation: Modulation is moving from one key to another within a piece, with a new tonal centre that settles in for a while, for example going from C major to G major.

N

Natural minor scale: The natural minor scale is a seven-note scale with the formula 1 2 ♭3 4 5 ♭6 ♭7, the foundation of every minor key, for example A B C D E F G.

O

Octave: An octave is the 12-semitone interval between two notes with the same name, the higher one vibrating twice as fast: on one guitar string it spans 12 frets.
Open chord: An open chord is played in the first three or four frets and lets at least one open string ring as part of the chord, like C (x32010), G (320003) or Em (022000).
Open tuning (Open G, Open D): An open tuning sets the open strings to a major chord, such as Open G (D G D G B D) or Open D (D A D F# A D), ideal for slide guitar.

P

Parallel minor: The parallel minor of a major key is the minor key with the same tonic but different notes: C minor is the parallel minor of C major.
Perfect fifth: A perfect fifth is the interval of seven semitones, as from C to G or A to E: the most stable interval after the octave, and with the root it forms a power chord.
Perfect fourth: A perfect fourth is the interval of five semitones, as from C to F or E to A: it is the distance between almost every pair of neighbouring guitar strings.
Phrygian mode: The Phrygian mode is the third mode of the major scale, with the formula 1 ♭2 ♭3 4 5 ♭6 ♭7: a dark minor mode recognised by its flat second.
Power chord: A power chord is a two-note chord made of a root and its perfect fifth (often with the root doubled an octave up), written with a 5: E5 = E B.

R

Reharmonization: Reharmonization means replacing or enriching the chords of a piece while keeping its melody, for example turning C Am F G into Cmaj7 A7 Dm7 G7.
Relative minor: The relative minor of a major key is the minor key with exactly the same notes and key signature, built on the major scale's sixth degree, a minor third lower.
Roman numeral analysis: Roman numeral analysis labels each chord in a progression by its scale degree in the key (I, ii, V7...), with upper case for major chords and lower case for minor.
Root: The root is the note a chord or scale is built on and named after: in a C major chord (C, E, G), C is the root and every other note is measured from it.

S

Scale: A scale is an ordered series of notes from a tonic up to its octave, defined by a fixed pattern of intervals, such as the major scale: whole, whole, half, whole, whole, whole, half.
Scale degree: A scale degree is a note's position in a scale, numbered 1 to 7 from the tonic: in G major, G is degree 1, D is degree 5 and F# is degree 7.
Secondary dominant: A secondary dominant is a dominant seventh chord that resolves to a chord other than the tonic, such as A7 to Dm or E7 to Am in C major.
Semitone (half step): A semitone, or half step, is the smallest interval in Western music: on the guitar it is the distance of one fret, and twelve of them make an octave.
Seventh chord: A seventh chord is a four-note chord: a triad with a seventh added on top, such as Cmaj7 = C E G B or G7 = G B D F.
Sharp and flat: A sharp (#) raises a note by one semitone and a flat (♭) lowers it by one semitone: on the guitar, that means one fret higher or one fret lower.
Shell voicing: A shell voicing strips a seventh chord down to three notes: root, third and seventh. It is the simplest and clearest way to play jazz chords on guitar.
Slash chord: A slash chord is written Chord/Note: the chord comes before the slash and the lowest note after it. C/G means a C major chord with G in the bass.
Standard tuning: Standard guitar tuning is E A D G B E from the lowest string to the highest: perfect fourths between strings, except a major third between G and B.
Strumming pattern: A strumming pattern is a repeated sequence of downstrokes (D) and upstrokes (U) across the strings, placed on the beats and offbeats of each bar.
Subdominant: The subdominant is the fourth degree of a key and the chord built on it (IV), which moves the music away from the tonic and often prepares the dominant, like F in C major.
Sus chord (sus2, sus4): A sus (suspended) chord replaces the third with the fourth (sus4: 1 4 5) or the second (sus2: 1 2 5), so it is neither major nor minor.
Swing: Swing is a way of playing eighth notes unevenly, the first long and the second short, based on a triplet feel, typical of jazz, blues and rock and roll.
Syncopation: Syncopation is attacking a note or chord on a weak beat or offbeat and holding it through the next strong beat, which shifts the accent away from where the ear expects it.

T

Tablature (tab): Tablature (tab) is a guitar notation with six lines, one per string, where each number shows which fret to play: it tells you where to put your fingers, not the rhythm.
Target notes: Target notes are notes of the current chord, especially the third and seventh, that a soloist lands on at strong beats and chord changes so the solo outlines the harmony.
Tempo (BPM): Tempo is the speed of a piece's pulse, measured in beats per minute (BPM): at 60 BPM each beat lasts one second, at 120 BPM half a second.
Time signature: A time signature, written as two numbers such as 4/4 or 6/8, tells you how many beats each bar contains and which note value counts as one beat.
Tonic: The tonic is the first degree of a scale and the centre of gravity of a key: the note and chord (I) that music returns to for rest, like C in C major.
Triad: A triad is a three-note chord built by stacking thirds: a root, a third and a fifth, such as C, E and G for a C major chord.
Tritone: A tritone is the interval of six semitones, three whole steps, as from C to F#: it splits the octave in half and creates the tension of dominant seventh chords.
Tritone substitution: Tritone substitution replaces a dominant seventh chord with the dominant seventh whose root is a tritone away, for example D♭7 instead of G7 before Cmaj7.

U

Ukulele tuning: Standard ukulele tuning is G C E A from the 4th string to the 1st, a re-entrant tuning: the G string sounds higher than the C and E strings.

V

Voice leading: Voice leading is the craft of connecting chords by moving each note as little as possible, holding common tones and resolving tensions by step.
Voicing: A chord voicing is the concrete layout of a chord's notes: which octaves, in what order, which notes are doubled or left out. One chord can have dozens of voicings.

W

Whole step (whole tone): A whole step, or whole tone, is an interval of two semitones, also called a major second: on the guitar it is two frets on the same string, as from C to D.
Whole-tone scale: The whole-tone scale is a symmetrical six-note scale built entirely from whole steps (1 2 3 #4 #5 ♭7), with a floating sound that suits augmented chords.

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