Keywords: outside playing, jazz, improvisation, atonal, synthetic scales, exotic scales
When I practice ‘outside playing’ I try to look for interesting scales containing all the notes of the chord I improvise over. The idea is to change rapidly change from one scale to the other, or even mix scales, or again, split them up, only using a few notes from each across different ranges. This permits very atonal results without sounding too random or chromatic. The diagrams below show some of the scales I use over Major and minor seventh chords (some scales can be named differently). Note: changing Cmin7 to Minor, or C Maj7 to Cmaj7b5 would naturally allow different scales to fit in.
Some alternative scales for C Major 7 and C minor 7 chords