Mobile and social music app Songza is gaining traction on Facebook and via mobile phones and now counts more than 500,000 users since its launch in September 2011. We caught up with Songza's CEO Elias Roman recently and he talked to Beet.TV about how the digital music service works.

"Songza is a music service for people who love discovering music but don't know exactly what they want to listen to," he explained. "We have expertly curated playlists by mood, situation, genre, decade, element of pop culture."

The app is available on the iPhone, iTouch, iPad, Kindle Fire, Android devices and also via Facebook, where it's become quite popular. In a recent blog post, Facebook said that Songza, and other music apps including Spotify and Deezer, are "seeing dramatic increases in sharing and music discovery." In fact, Facebook users have shared more than 5 billion songs through those apps. Songza is one of Facebook's timeline apps.

While competition is rife in the digital music business, Roman said Songza is aiming to stand out via its playlists. If a user wants a playlist for a cocktail party, he or she can search for that via the service. Other playlists are tailored for working out, for walking through the city, for casual dinner parties and more. Each playlist can be shared via social networks or saved to a collection.

The Songza service is free of charge with no listening limits or audio ads. The company is relying on two revenue streams. They include banner ads from sponsors and working with media companies to build on top of the Songza platform.

Daisy Whitney