Google on Tuesday began letting people store music collections in virtual online libraries in a challenge to Apple's popular iTunes shop as well as a similar service from Amazon.
Google Music does not sell songs but allows users to store personal collections in the Internet "cloud" for streaming to smartphones, tablet computers or other gadgets.
Google Music is being rolled out on an invitation-only basis in the United States to test the service, which the California Internet giant envisions eventually making available worldwide.
"When you add your music to the new service, you can listen to it on the Web on any compatible device," said Google product manager Paul Joyce.
Google was getting around having to cut deals with music labels by letting people store digital versions of songs they already own in online "lockers" which they can access using gadgets linked to the Internet.
As many as 20,000 songs could be stored at Google Music, Joyce said at the Internet search giant's annual developers conference in San Francisco.
The music service is a "compelling platform" for eventually selling digital music, according to Google director of digital Jamie Rosenberg. "It has been in our interest and has been in our plans to work with the music industry to sell music,
"Unfortunately, some of the major labels were only interested in doing so on terms that were unreasonable," he said. "That isn't going to stop us."
Rosenberg contended that Google Music is "a completely legal" service akin to a person storing music collections on home computer hard drives.
Stored music could be streamed to gadgets but digital files cannot be downloaded for sharing or copying.
Google Music takes aim at a similar service launched in March by Internet retail powerhouse Amazon.com and is a long-coming step toward taking on Apple's iTunes digital content shop.
"Google is trying to differentiate its Android platform because they want Android to dominate," said Wedbush Morgan Securities managing director of research Michael Pachter.
Pachter said the move was a necessary tactic to keep Android devices popular in the fierce smartphone and tablet markets but shouldn't be a big deal for consumers who already have options for getting or storing music online.
"Another vendor of the same content at the same price isn't very exciting," Pachter said. "But, by integrating it into all Android devices Google can make a competitive advantage for Google."
Google also used the opening of its developers conference to announce it is adding movie rentals to its Android Market offering digital content for devices running Android software.
Invitations can be requested at www.music.google.com. The Google Music Service is free for the time being.