There are a whole stack of music/media players available for Linux, audio or video or both..
http://lindesk.com/2008/03/top-10-linux-mp3-players/--I usually use Songbird, for example..
Unfortunately like some(many) successful Linux or OSS projects, once good success arrives, they quite often abandon Linux for greener pastures ($cash, that is..)
--and sometimes don't even consider being cross platform: perhaps that is a knock-on effect of their new market?, who knows for sure..
CD rippers simply provide methods of converting and ordering playlist or tracks in mp3 or other formats..
Linux often includes a place in your /home directory for video or audio files (music is the name in a Gnome and some other window managed desktops (the normal GUI interface..))