There are 6 tiers of music fandom: 

1.  Never heard of them.
2.  Never heard of them.  Oh wait, they sing that?  I like that song.
3.  I like 2 or 3 songs by them.
4.  I love that one album.
5.  I like several of their albums, but none of the old/new stuff.
6.  I can recognize every single song from every one of their albums by only hearing the first three notes.