Here are some chord types, and associated scales commonly used to play over them
|I major, I 6, I maj7
|I minor, I minmaj7
||Melodic Minor, Harmonic Minor
||Dorian, Phrygian, Aeolian
|min6, II min7 and all other min7s
||Mixolydian, Lydian b7, Altered, Whole Tone, Diminished (H-W)
|All other 7th chords
Notes about Chord-Scale relationships:
There are no rules associated with these suggested relationships.
Use them as a guide but do not regard them as definitive.
Your ear is ultimately the best judge.
Chords are often listed according to their Roman Numeral. Roman numerals relate
to how a specific chord is used in a progression relative to the key of the tune. In the key
of C, the III min7 chord is Emin7.