LOS ANGELES (AP) - The music-subscription company Spotify is joining Pandora, Slacker and Songza in offering a free radio service for mobile devices in the U.S.

Until now, the company charged customers $10 per month for use of its mobile app.

The free service, which comes with audio ads, is a way for Spotify to entice people to sign up for a paid subscription, which strips out the ads and enables users to choose songs. The new feature is available only for iPhones and iPads for now.

Non-payers will be able to listen to genres of music based on similarities to an artist, album, song or playlist they've created within Spotify. They will also be able to give songs a "thumbs up" for playback on computers later on.