- It's forbidden (forum rule) to add music/flash-based in the signature.
- when it's playing a music, it will stop when you load another page of the topic, not useful to put it in a signature :/
- If someone wants to listen to music, he can do it without your help.
- I'm sure you are not the author of the music you want to provide, and you don't hold any copyright. It's forbidden to provide audio without asking the original author, and without paying author's right too.
I know people are uploading music on youtube, but it's forbidden too, they just don't care and never read the rules.