The achievement guide posted by TTerBNZ is fine, but here are a couple of addenda:
1) You cannot quit out during a song. You have to let the entire song play out for it to count for a win.
2) The stars you earn during the song(s) count towards your single-player progress, so don't hesitate to make an effort.
3) Guitar mixes don't count towards this achievement. At all.
Yes, 'addenda' is a word. It's a plural of 'addendum'.
Scratch and spin onwards, my dudes.