One thing I never heard people talking about is Hexatonic scales, Usually we either deal with pentatonics (5 notes), or diatonics (7 notes), but hexatonics fall right in the middle.
You can think of it as either a diatonic minus 1 note, or a pentatonic with 1 extra note.
This particular hextaonic scale that I’m showing here (minor pentatonic plus the major 2nd) has a cool sound and you can create some “Eric Johnson” sounding licks.
Check it out.