The site, redesigned by Rufus Leonard, integrates O2's music offering online, supporting the use of the Digital Music Player, which allows users to buy tracks from the catalogue, and also promotes its range of music handsets.
In addition, it offers information on artists, details of tracks and upcoming events and other products to buy, such as ringtones and wallpapers.
The relaunch comes as rival companies 3 and Vodafone push music downloads as one of the incentives for people to take up subscriptions to third-generation mobile phone services.
Megan Forster, music marketing manager at O2, said: "Music plays a really important role in the lives of our target 15- to 35-year-old audience and we feel this site provides them with the range of information, services, tracks and downloads they are looking for."
Rufus Leonard designed the site and is also responsible for building, management and hosting it.
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