MySpace, the popular social-networking site, plans to turn up the volume in the online music market when its joint venture with the biggest music industry players finally delivers its much-awaited service.

MySpace Music, slated to go live on Thursday, will offer members of the social-networking site the ability to stream for free music from the four major record companies, as well as buy songs for download without any digital locks from a store powered by Amazon MP3.

In addition to EMI Music, Sony BMG Music Entertainment, Universal Music Group and Warner Music Group, other major players on board are publisher Sony ATV / Music Publishing and independent music distributors The Orchard and Alternative Distribution Alliance.

MySpace Music, announced in April, builds on the social-networking site's existing and significant music component, which includes profiles for more than 5 million artists along with songs, videos, photos and other content.

The new service will allow MySpace members to share music, purchase merchandise and event tickets, stream and buy songs, manage their digital music collections and compile playlists.

"Music has been a big part of MySpace since the beginning, and especially in the early days it was the heart and soul of what we were about. Since then, we've spent a lot of time trying to figure out what else can be done in music and where can we go from here," said Steve Pearman, senior vice president of product strategy for MySpace.

While the market has been dominated by Apple's iTunes music store and iPod players, MySpace believes its new service will take online music to another level by giving people more flexibility and freedom to share with friends and load songs onto different devices.

"We believe you can move the music monetization model away from a system based on scarcity and barriers and build as strong, if not a stronger business, by setting the content free," Pearman said.

That approach is consistent with the principles that govern the MySpace user experience, like social discoveries and sharing and consuming content, he said.

At the same time, MySpace Music seeks to simplify the pairing of brand marketers with artists for advertising purposes, while giving music labels and artists viable, alternative revenue streams, he said.

On Thursday, when the service goes live, MySpace subscribers in the U.S. will encounter a new page in their profiles called "My Music" where they will be able to create playlists. My Music will contain a default initial playlist called "My Profile Song History" that contains all the songs subscribers have added to their profiles until now.

Users will be able to add a playlist of their 10 favorite songs to their profile home page. Beyond this, they'll be able to create as many other playlists as they wish, and each one can contain up to 100 songs. Playlists can be public or private.

The music search engine has been improved so that users can search not only by artist name but also by song and album titles. Until now artists could only make available six songs, "so when I would search, it only really made sense for me to search for a particular [artist] because I didn't have a realistic expectation that they would have the particular song or even album I was interested in," Pearman said. "This project goes into the deep catalogue" thanks to the broad participation of label partners.

As songs are returned in search results, they can be dragged and dropped into the music management tool. To listen to the songs, users call up a MySpace pop-out music player. The songs aren't stored in local PCs, but rather on remote servers, so they're accessible from any PC by logging into MySpace.

"Wherever you go, as long as you have an Internet connection, you get access to all your music -- full tracks, as much as you can eat, no limitation on how many times you listen to songs nor to how many songs per month," he said.

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