A monthly subscription to BBM Music will cost $4.99 in the U.S., but 'may vary by country and will be announced upon availability in each country,' RIM said in its release. (Eric Risberg/Associated Press)

A social networking service that allows BlackBerry users to share a cloud-based music library with their friends has been announced by Research in Motion.

The subscription-based BBM Music service launches as a closed beta trial Thursday in Canada, the U.S. and the U.K., the Waterloo, Ont.-based company announced in a news release. It will be commercially available in 18 countries around the world later this year.

The new service allows each user to create a profile with 50 favourite songs, picked from a catalog made available through agreements between RIM and Universal Music Group, Sony Music Entertainment, Warner Music Group and EMI. Half of the songs can be exchanged for 25 new songs each month.

The songs are stored on a server managed by cloud-music provider and RIM partner Omnifone.

The songs in a user’s profile are shared with all the friends added to his or her "BBM Music Community" social network. The more "friends" a person has in her network, the more songs she can listen to or add to her playlists.

"A major component of online music continues to be about community, and the ability to discover new artists and music through word of mouth," said Rob Wells, president of global digital business for Universal Music Group, in a statement.

"BBM Music dynamically and elegantly integrates the excitement of this social music discovery process with a high quality music service."

Many other internet music services such as Spotify, Rdio and iTunes  also have a similar social networking component.

A monthly subscription to BBM Music will cost $4.99 in the U.S. and Canada, but "may vary by country and will be announced upon availability in each country," RIM said in its release. It also noted that data charges may apply for users with limited data plans.

Alternative to streaming available

Unlike some services such as and iTunes Ping that only allow users to play short previews of songs shared by their friends, BBM Music will allow users to share full tracks. In addition to streaming the songs, users can save them to a mobile device to listen to when they don’t have wireless coverage.

BBM Music will be linked to the BlackBerry Messenger service (BBM), an internal instant messaging network for BlackBerry users that can be used as an alternative to text messaging.

The launch of BBM Music follows the launch of similar cloud-based mobile music streaming services for Apple and Android mobile devices, which give users access to their music collections without having to store all their songs on multiple devices.

Amazon launched its Amazon Cloud Player  for the Android mobile operating system in March. Apple CEO Steve Jobs announced the similar iCloud service two months later.

On Thursday, a number of technology columnists suggested BBM Music is not very good value for money compared to competing music streaming services.

"For $5 per month, you only get 50 songs for that period. If you want more than that, you'll have to hope your friends have BBM and are willing to shell out $5 per month so you can listen to the 50 tracks they chose," wrote Steve Kovach on the Business Insider website.

He noted that Spotify, which is available in the U.S. but not Canada,  allows users to access an unlimited number of songs with no limits for $5 per month or $10 per month with mobile access.

Jordan Crook, a columnist for TechCrunch, also believes that with BBM Music "the bang you’ll be getting per buck isn’t all that great, especially if you’re lacking in the social department."

He added, "But you have to applaud RIM for testing out the musical waters this way. They’re basically forcing users to invite and add friends because the more friends you have, the more music you can access."