I think the post about two turntables and a microphone being a universal interface for people with records vs the fractured digital interfaces is particularly interesting, here http://music.columbia.edu/pipermail/music-dsp/2010-November/069349.html and also the talk about how the medium (vinyl) has dynamics requirements that force the signal to be compressed before it's put on record and that emulating that might give the same effect to digital music http://music.columbia.edu/pipermail/music-dsp/2010-November/069388.html