I might be wrong but I thought Moby came long after Philadelphia. Didn't Moby start around 1999/2000 and the film was made in the early nineties I thought.
i thought Neil Young's Philadelphia was at the end - when they're watching the home video footage etc. Piano track, high pitched voice? But admittedly the Bruce Springsteen track (Streets of Philadelphia) does sound a bit like Moby cos it has mournful synths and slightly deadpan vocals.