When trying to use a song from either youtube or iTunes as a template to record from, I have this problem where the song records into the mix. What I am trying to do (and have tried all avenues I can think of) is find a way of muting/cancelling the external audio and have only my own vocals (guitar, etc.) make it through; essentially being able to make a duplicate of the original song.
I am using a pre-amp (“ART USB Mix - Three Channel Mic-Inst-Line Mixer - Computer Interface”). I am using Windows 7, and Audacity 1.3.