Thanks ant1 for the tutorial! I've tried it out, and I've got a song out of it which I'll probably use on BotB as soon as I have a couple of issues ironed out with it.
I've found a strange error that detunes some of the arps I use in the song when I convert to song into a .sid. Also, know any good ways to delete swm files? i'm looking to sort out the arp issue but I've run out of save space on the .d64 I'm using to make a new save