Hi! I am currently practising modes, scales and walking bass. And as a beginner to jazz, I was jamming around some basic jazz chords progression; Dmin7, G7, Cmaj7, A7 Problem hit me when I played the A7 and what I thought should be the mixolydian mode. Correct me if I am wrong, but apparently there is a flat 6 in there, something that makes it a melodic minor fifth mode? Now how do I know when there should be a melodic minor mode or a plain major mode?