that's because it's legal...if you want pink floyd either buy it or download/stream illegally, they (the record company i guess) don't want their music on spotify. simple as that. (same for the beatles, and quite a lot of other bands, but there's still a lot of good music on there imho, especially for a free/advertising based program)

dirtbombs! oblivians! quintron! strange boys! it's got it all