Internet music service Rdio.com on Tuesday unveiled a redesign intended to make it \"faster, simpler and more social\" as it battles with rivals such as Pandora and Spotify. Rdio also announced that its music catalogue has grown to more than 15 million songs. Rdio was created by Skype founders Niklas Zennstrom and Janus Friis and the subscription-based advertising-free service was opened to the public in August 2010. \"We\'ve made Rdio bigger and better with new features that really make discovery fun,\" vice president of product Malthe Sigurdsson said in a release. \"This is more than just a redesign; the new Rdio transforms the boring, spreadsheet-like way of consuming digital music into something visual and dynamic.\" Social features include being able to share music with friends by email or at social networks Facebook or Twitter. The revamped service was rolled out on Tuesday in Australia, Canada, Germany, Spain, Portugal, Denmark, New Zealand and the United States. Rdio charges $10 monthly for an \"unlimited\" subscription that lets music be streamed to someone\'s Internet-linked computers and mobile gadgets. Rdio is vying for fans in a streaming music arena that has proven to be a tough place to make money. That fact has not deterred competitors, with Europe-based Spotify bursting into the US market last year and Internet titan Google fine tuning its online music offerings.