Yeah, the only music you can legally host are remixes (or conversely, soundtracks that have been legally made available for redistribution). Even if the soundtrack is 20 years old and out of print, it's still illegal to distribute.
However, like Serio said, game companies and labels (unless they have the words 'Square' and 'Enix' in their names) don't care because the market is too small. You can't do that with mainstream media. Once in awhile though you'll see a dojin producer specifically request that his work not be distributed...