Although it has been available for only a couple of days, MySpace Music has already sparked controversy, as it apparently excluded hundreds of music labels representing popular artists such as Arctic Monkeys, Franz Ferdinand, Bjork and Tom Waits.

The music service is a joint venture between News Corp’s MySpace and the four most important music companies out there: Vivendi’s Universal Music Group, Sony BMG Music, Warner Music Group and EMI Music.

MySpace Music offers free access to an impressive collection of hundreds of thousands of songs supplied by all four major labels and, in addition to this, users are able to transfer songs on their portable music players, even if they have to pay for downloading them from Amazon.com.

However, the much talked about problem with MySpace Music is that it failed to come to an agreement with several independent labels and, thus, numerous well-know artists have been left out.

Furthermore, Merlin, a music licensing agency, expressed its disappointment with regard to the fact that MySpace launched its music service while the company was still in negotiations with some labels.

Merlin hopes to obtain an agreement similar to the one acquired by the four major labels. Still, MySpace explained in a statement that the company had put forward a deal for Merlin which would offer “equal opportunities to Merlin’s Labels and Merlin’s artists that we have provided to all labels and artists.”

It’s hard to believe that by excluding indie artists from its Web site MySpace Music will be able to outshine the largest music retailer, iTunes. The rise or fall of the service should be interesting to watch, though.