Jazz guitar scales · Concept
Two eight-note scales built from alternating steps, and the symmetry that makes them enormously economical on a guitar.
Half-whole — semitone, tone, semitone, tone — goes over dominant chords, especially a 7♭9. It supplies the ♭9, ♯9, ♯11 and 13 while keeping the natural fifth, which is exactly the set of tensions a 7♭9 wants. Whole-half — tone, semitone — goes over a diminished seventh chord, whose four notes it contains.
Getting them the wrong way round is the most common mistake with these two, and the tool will not let it happen: a half-whole scale does not contain the ♭♭7 that a diminished seventh chord depends on, so it is never offered for one.
| Scale | Notes | Formula | Against the chord | Usage |
|---|---|---|---|---|
| A Half-whole diminished | A Bb C C# D# E F# G | 1 b9 #9 3 #11 5 13 b7 | 1 b9 #9 3 #11 5 13 b7 | Best choice |
| A Altered scale | A Bb C C# Eb F G | 1 b9 #9 3 #11 b13 b7 | 1 b9 #9 3 #11 b13 b7 | Common |
| A Phrygian dominant | A Bb C# D E F G | 1 b2 3 4 5 b6 b7 | 1 b9 3 11 5 b13 b7 | Common |
| A Major pentatonic | A B C# E F# | 1 2 3 5 6 | 1 9 3 5 13 | Colour |
Both scales repeat every minor third, which means there are only three distinct diminished scales in all twelve keys. One shape, moved up three frets, is a different scale name and the same notes. For a guitarist this is the cheapest material on the instrument: learn one box and you have covered four roots.
| Scale | Notes | Formula | Against the chord | Usage |
|---|---|---|---|---|
| E Whole-half diminished | E F# G A Bb C C# D# | 1 2 b3 4 b5 b6 6 7 | 1 9 b3 11 b5 b13 bb7 7 | Best choice |