BBM Music is a cloud-based service that enables users to build a library of songs to share with friends through the BBM messenger service, which has 45 million users worldwide.
RIM has agreed deals with the major labels - Universal, Sony Music, Warner Music and the now Universal-owned EMI - to create an extensive catalogue of music.
The company says that the key differentiating point about BBM Music is that it is a "truly social community-based music experience", allowing subscribers to compile playlists of 50 favourite songs and then share them with the BBM community.
The more contacts users add to their BBM Music network, the bigger their music library will become due to access to a greater number of playlists.
BBM Music users can swap out up to 25 tracks every month to keep their playlists fresh and up to date. Tracks can be streamed, or cached to BlackBerry smartphones for listening offline.
A dedicated app for the service allows users to see a "visual timeline" of the recent updates of all contacts within their community, giving a chronological view of new friends and songs added.
"More than 45 million customers already love the social communication benefits delivered through BBM and we are thrilled to be extending the experience into a uniquely social and interactive music service," said Mike Lazaridis, the president and co-chief executive at Research In Motion.
"We have partnered with leading music companies to provide a 'full track' music sharing and discovery experience that will provide users with quality music on demand and allow them to connect with friends on a whole new level."
"BBM Music dynamically and elegantly integrates the excitement of this social music discovery process with a high-quality music service, enabling tens of millions of BlackBerry users to experience new music and to share those experiences with their friends virtually anywhere and at anytime."
Warner Music executive vice president of digital strategy Michael Nash added: "A dynamic social music experience is a powerful way for our artists to connect with fans and also for fans to discover music by interacting with each other.
"Addressing more than 45 million BlackBerry Messenger users with a service tailor-made for its mobile community, BBM Music has the opportunity to reach a broad and engaged audience."
BBM Music, first announced back in September, is available now in the UK for a monthly subscription of £4.99.
BBM has grown by almost 20 million users worldwide over the past year, but the service was hit by a major global outage last month that damaged the BlackBerry brand.
Cloud-based music provider Omnifone is handling the back-end solution of BBM Music for RIM, including content management, hosting and all reporting duties.
Also today, RIM has announced the launch of a new touch and QWERTY BlackBerry Bold 9790, along with an all-touch BlackBerry Curve 9380 smartphone. Both handsets will become available in stores and from mobile carriers "over the coming weeks".