So @Krill, your idea of writing to SID only on init breaches the length rule #6.
Music must contain melody and rhythm. But if John Cage's 4'33" is music to you then, anything counts, even silence, so why even bother, a single RTS counts as a sid =)
Hmm, why not just make it a hard 16 second (802 frame) limit to avoid any doubt or quibbles?
As iAN's already pointed out, there's no real benefit to this. No current players would be affected by it, and it's really down to SID player implementers to add a feature like "don't skip to next track until at least a minute's worth of repeats of current track" if that's what you want.