Seattle-based RealNetworks Inc., operator of the Rhapsody digital music service, revealed today that it has launched an online music store that will compete head-to-head against iTunes and other popular digital music retailers. RealNetworks said the Rhapsody-branded servic, will offer most of its songs for 99 cents and most of its albums for $9.99. All downloads, the company added, will be in the popular MP3 format, which can be played on most any portable music device and which is free of proprietary digital-rights-management restrictions. To promote its new service, RealNetworks said it will award free albums to the first 100,000 people who register with Rhapsody and shop before the Fourth of July. Additionally, RealNetworks said its service will offer shoppers full-length song playback instead of the 30-second samples available with competitors, such as iTunes.