The .snd files could contain the music; they might be already extracted from what you say, it's a matter of figuring the playback codec / sound format. Other files, .bin etc we couldn't know, unless you post the files/sources.
Music is very much likely ADX, vgmtoolbox can extract those. In fact, some of those bin's and snd's could be the adx files themselves, which means you can probably just change the extension to adx. If you're trying to get your hands on sfx, use psound since most games on ps1 and ps2 used sony vag as the primary codec for sfx.