Glossary

The same note twice — zero semitones apart.

One semitone — the smallest step, and the most dissonant. Think of the Jaws theme.

Two semitones — one whole step. The opening leap of Happy Birthday.

Three semitones — the interval that makes a chord sound minor. Think Greensleeves.

Four semitones — the interval that makes a chord sound major.

Five semitones — the distance between most adjacent guitar strings. Think Here Comes the Bride.

Six semitones — exactly half an octave. The restless, unstable one, historically nicknamed the devil's interval.

The tritone splits the octave in half, so it is the only interval that inverts to itself — six semitones up and six semitones down land on the same note name.

It is also written as an augmented 4th (♯4) or a diminished 5th (♭5), depending on how it is spelled. That is why the ♭5 appears as the blues note in a blues scale and as the tense core of a dominant 7th chord.

Seven semitones — the most consonant interval after the octave, and the root of the power chord.

Eight semitones. It inverts to a major 3rd, so it carries a bittersweet colour.

Nine semitones — warm and open. The NBC chimes.

Ten semitones — the ♭7 that gives dominant and blues chords their pull.

Eleven semitones — one semitone below the octave. Lush and jazzy, and a big leap to sing.

Five movable shapes — named after the open C, A, G, E, and D chords — that link every position of a scale or chord across the neck.

Every chord and scale can be played in five shapes, each based on one of the five open chord forms. Slide a shape up the neck and it stays the same chord, just in a new key.

The five shapes interlock: where one ends, the next begins. Learning how they connect is what turns isolated boxes into the whole fretboard.

Seven patterns that play a seven-note scale with exactly three notes on every string.

Where CAGED gives five shapes of varying width, 3NPS gives seven even ones — each starting on a different degree of the scale, with three notes on all six strings.

The regular three-per-string layout suits legato, sweep, and fast alternate picking, which is why rock and metal players tend to favour it. It only exists for seven-note scales, so pentatonic and blues scales have no 3NPS patterns.

A three-note chord — a root, a 3rd, and a 5th. The smallest complete chord.

The same chord with a note other than the root in the bass: 1st inversion puts the 3rd lowest, 2nd inversion the 5th.

The notes are unchanged — only which one sits at the bottom. That small change smooths the bass line between chords and softens the root's weight.

A chord written as chord/bass, like C/E — play a C chord, but put E in the bass.

Most slash chords are simply inversions: the bass note is already part of the chord. C/E is a C major triad with its 3rd in the bass.

One particular way of arranging a chord's notes on the neck. Same chord, different shape and colour.

A note's position in the scale, counted from the root: 1 is the root, 3 the third, 5 the fifth.

Degrees describe a scale independently of key, which is what makes a shape movable: the 1-♭3-5 of a minor chord is the same pattern whatever fret you start on.

The note a chord or scale is named after and built from — degree 1.

Lowers a note by one semitone. As a degree, ♭3 means the 3rd lowered a semitone.

Raises a note by one semitone. As a degree, ♯5 means the 5th raised a semitone.

The 5th lowered a semitone — the blues note, and the same distance as a tritone.

The 7th lowered a semitone — what makes a chord dominant rather than major.

The ♭5 added to a minor pentatonic scale — the passing tone that gives the blues its grit.

A note outside the scale, used to pass between scale tones.

A colour tone borrowed from the chord's upper structure — 7ths, 9ths, and altered tones.