»In which our hero triumphs over the OS

I finally corralled my music, all of it, onto a modern version of OSX.

This all came about because OSX cheerfully upgraded the firmware on my iPod to a version that was incompatible with the verison of iTunes with which it synchronized. No problem: a subsequent run of Software Update helpfully told me to update iTunes. The two still would not talk to each other, and a little poking 'round in Apple's Knowledge Base uncovered the problem: I needed the shiny new iTunes 7, which does not happilly coëxist with OSX10.2, which, you know, isn't broken so why should I fix it?
I painstakingly backed up the old g4, and gingerly set up a brand-new Mac Mini (the dual-core Intel version). A few hours of rsync later, I had all of the metadata from the g4 copied to the Mini, and had connected the music-containing hard drives.
Amazingly, nothing blew up. Everything worked! The iPods sync'd happily, music continued to play, and life seems swell.