In an effort to better compete with a juggernaut like Spotify, Rhapsody is using one of the world's most popular social networks to showcase and promote its music-streaming service. Today, at SXSW 2015, Rhapsody announced that it's bringing more than 30 million songs to Twitter, allowing users of the microblogging platform to streams songs directly from it -- for free. The audio-subscription service is using Twitter Cards to let people stream and share their favorite tunes, regardless of whether or not they have a paid Rhapsody account. So, what's the catch? It's simple: Rhapsody's hoping that those who see these audio-embedded tweets, on iOS or Android, will want to hear more and end up on a landing page that's set to offer a free trial.