Altered scales are most often played over dominant seventh chords. They introduce flattened fifths, sharpened fifths, flattened ninths and sharpened ninths, giving the full range of altered notes beloved of jazz improvisers.
Altered scales are used predominantly by jazz musicians to produce interesting tensions while improvising over dominant seventh chords.
Diminished scale guitar fretboard diagrams, tab and information. Learn how to play diminished scales on guitar.