I need to play a G major chord recorded in MP3 or WAV. Then I need to very slowly fade to a G minor chord, also on MP3/WAV. The fades back and forth are over about 15 seconds when directed by the Arduino. Stereo not needed.
My idea is to record one chord on the left track and one on the right track. Then play the recording in a player shield and have Arduino slowly change volumes of L up and R down.
I have not been able to find a shield where the vols of L and R can be controlled independently. Anyone know of one? Anyone have an idea for alternate approach?