In a bid to broaden its audio service and differentiate itself from competing in-house DVR offerings by cable and satellite providers, TiVo has signed a deal with RealNetworks to allow its subscribers to listen to songs from the Rhapsody digital music service on their televisions.

The partnership is a way for both TiVo and Rhapsody to boost their subscriber bases. Users whose TiVo boxes are connected to the Internet can now sign up for RealNetworks' Rhapsody music service for $12.99 a month (on top of what TiVo charges for its service) and download any of four million digital songs available.

The announcement follows similar deals with Amazon's Unbox service for movies and TV shows and with Yahoo for photo sharing as the company strives to convince consumers that it's a home entertainment service with features that go well beyond what any DVR does.