One little theory hang-up
I know all the modes and how they connect. My one issue is; what scales can I play when a song is in a certain key ? eg. if a rhythm is playing in the key of A maj, and I want to start soloing over that track; Should I play the major scale in the 5th position (ionian mode beginning at 5th fret), or can I play the pentatonic minor scale (from the Aeolian mode) in that 5th position ? Once I get started, I know where to go, but I have seen conflicting information on which scale to play in the key position. Thanks in advance.