My absolute favourite short song is Away Goodbye by Change of Heart, they're another underrated Canadian alt-rock act from the 90s.
The song isn't even a minute long but it packs just as much punch and most full length pop tunes. I really like how it starts off with just an acoustic guitar and a voice before exploding with the full band without ever losing the feeling of intimacy or intensity. Unfortunately the individual song itself isn't available on youtube but surprisingly enough the entire album it happens to be on is, so here's a link cut to the right time
Change Of Heart - Tummysuckle (1995) Full Album - YouTube
The whole album is worth listening to as well but this track is its pinnacle to my ears.