Sony BMG, Warner Music and Universal have confirmed their backing for the venture, which was revealed last year (Marketing, 4 April, 2007).
The service is intended to rival Apple's iTunes Store. MySpace will support free music and video-streaming with ads, ringtones, paid-for downloads and sales of concert tickets and merchandise.
Currently, iTunes accounts for more than 70% of digital music sales. MySpace is a well-positioned challenger, with nearly 30m unique users visiting its music channel each month.
MySpace Music claims to have the biggest collection of artist profiles, tour dates, blogs, music videos and photos in the world.