This is a pretty conventional rock song, in terms of structure: I-V-vi-IV in the verses, which is the same chord progression (in a different key) as Bush's "Glycerine" (as well as most other rock songs), but instead of it being any sort of driving, tempo-defining strumming pattern, it's an instantly recognizable "one-and...three-and-four-and-one-and..." that makes this one of relatively few 1990s alt rock songs in which the memorable, hummable part is not the lead guitar riff or a vocal line, but the background chords on rhyhtm guitar. It's so simple it's almost juvenile, and it's a testament to putting an unfamiliar spin on a familiar trope.
That's kind of what this song does, musically--it introduces something familiar, but uses the expectations that come with such a familiar style or structure to play with them. The result is a piece that hooks you in immediately with a slow head-bobbing/foot-tapping intro, then adds layers, piece by piece--like Beethoven's 7th--until we're in full-on party mode, never mind that the lyrics are about suicide and/or depression and/or addiction. Except "Santa Monica" never gets to thrashing along, it's still just head-bobbing/foot-tapping all the way through. The only difference is that by the end of the song, we've got lots of people head-bobbing/foot-tapping, not just one.
