In Western music, the major scale rules as king. As a maximally even scale, this 7-note wonder offers a harmonic balance that has fascinated people throughout many centuries. As a 7-note scale however, the major scale certainly is not alone. …
Heptatonic Scales with a 4-Semitone Maximum
This page is Allan Holdsworth’s main criterion for ‘usable scales’ applied to seven-note scales. Holdsworth chose to discard all scales that had more than 4 semitones in a row. He mentioned this in his 1992 REH video where he said: …