Google has 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. In a statement, Google Australia said it didn't "have a timeline to announce for an Australian release".
"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.
Invitations can be requested online at music.google.com.
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.
With Amazon Cloud Drive and Cloud Player, users can upload digital music, photos, videos and documents to Amazon servers and access the files through web browsers or phones and tablet computers running Google's Android software.
Music bought from Amazon.com or Apple's iTunes or from a personal collection is held in a digital "music locker" on the internet and can be accessed from computers running Internet Explorer, Firefox, Safari or Chrome web browsers.
Cloud Drive gives five gigabytes of free online storage to Amazon account holders and a free upgrade to 20GB with the purchase of an MP3 album. Users can also purchase 20GB for $US20 a year.
Google Music is free for the time being.
Apple sells music at iTunes and is reportedly working on an internet "cloud" storage service for streaming digital music collections but has not announced any plans.
Apple purchased an online music site called Lala.com in December 2009 which hosted digital music collections on the web.
"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.
Movie rental prices start at $US1.99 and films could then be streamed to any Android-powered device. People have 30 days to view rented movies, and must finish watching them within 24 hours of starting.
More than 100 million Android devices have been activated worldwide and 400,000 new gadgets powered by the Google-backed software are activated daily, according to Google product manager Hugo Barra.