I could not find mention of any such musicblocks in the wiki. If you own a rube or spinning wheel music block, or know someone who does, please add it to the wiki. www.glitch-strategy.com/wik...
Ok, I just went through my blocks. You're right. I was mistaken. There is no Rube music (unless it's XS-5 which is the only one I'm missing). DR-3 is the spinning wheel music.
In early IRC (?) chat programs, cntl-G would ring a bell or sound a beep to alert a friend who has wandered off or started to nap during a chat. Alas, it could easily be abused or I would suggest adding it to chat functionality.