If you want to put a music video in it, one way is to find a location the net that already has it and then just embed it.
Good source is:
The above sites will even give you the html/scriptlet you need to use to post it onto your page. Just copy it.
You can then go into your profile
1. My Ns 2. Profile 3. and paste it (control v)
Also. you can use .mid files (midi) they are fast, and quick and can run invisibly in the background without controls (as well as .mp3s along with a # of other audio formats)
You can go to google.com, search for "Midi download" or "midi database" and find a website filled with them. Find out where the source for the midi is (you can right click on it and go to properties).. it will look something like: http://www.website.com/folder/midi.mid
Once you know that, go into your profile and embed it like this:
< embed src=http://www.website.co/folder/song.mid
autostart=true loop=true >
And remember to delete the space between the less than and greater than sign so it's more squished together.