I've been reading all these posts about modes, and I think I finally got it, but want to make sure. Alright there's a song from my praise band that's in A flat Major. When the chord changes to D flat, that's the subdominant chord (IV), right? Which means I can play Db Lydian mode? Db - Eb - F - G - Ab - Bb - C - Db , is that right? I don't play the whole mode, I just make up fills using those notes, but is that the right mode?