Does Source support pre-loading music so that it continues/plays through loading screens? It completely breaks the immersion when there’s an ambient track and suddenly it just stops because you hit a loading screen. This is very noticeable in the tram ride; it’s bad enough that everything suddenly freezes in place, but it’s somehow worse that the ambience halts as well.
It especially sucks if you’re really digging the track and you inadvertently move into a loading area.