I made a distinction between retro and nostalgia in the "Music Post-Baudrillard" essay below, and I want to discuss it further by giving a quick example.
The interesting contrast between Burial (yes count me as another typical Leftists [temporarily] ex-raver fan), is that, while he renovates past styles, the music itself is not contingent on recognition. It works as music in and of itself. Contrast that with, say, the worst mash-ups or Girl Talk. With this music, retro to its core, the pleasure in the music is purely from recognition. If there is any interesting clash of meaning, some purposeful collision that alludes to a perspective on the part of the artist, it is incidental, possibly accidental (Rauschenberg didn't make these records). Rather the whole purpose of the music is to ask "do you remember?". Burial assumes you do. Burial knows you can't forget.