The Scale Omnibus e-book

460-page PDF with 400 musical scales in all 12 keys, with modes, synonyms, historical notes, tables to identify scales by intervals, associated chords, complete name index (1000+ synonyms!). New edition fixes duplicates and typos, adds new scales, include information about similar, subset and superset scales (i.e. scales that differ only for one note), and mirror scales. Over 5,000 hyperlinks allows you to quickly jump from one scale to its modes, similar scales, etc.

Not sure yet? download a free excerpt here.

You might also like The Scale Playground, the companion software for Mac/Windows. See it in action here: https://youtu.be/K5YGjHnWx8o