There are three design goals in mind.
I would like to be able to listen (stream) music at work where I can run my own applications but cannot store mp3s due to music copyright concerns. I want to be able to loop through a playlist over and over, and I would like to show on my MSN status what I'm listening to (just like what Windows Media Player does)
This YouTube player does all three of them.
Simply copy and paste the internet addresses (URLs) for all the YouTube music you want to loop through in the text field.