Sarah Tew/CNET

Spotify is setting its mobile app free.

The streaming music service said Wednesday that it would allow anyone on an iOS or Android tablet or smartphone to use its app free of charge. The new service launches Wednesday. Previously, users could only listen to Spotify's desktop or browser-based program for free, and only premium members who paid $10 a month had access to the service through other devices.

The move marks a change in Spotify's business and could expand its potential base of listeners. The lack of a free mobile app has been an inhibitor of the company's growth, and filling that void could help it keep its growth momentum going.

The tablet app works just like the desktop version, giving you access to specific select tracks.

The smartphone app, however, doesn't work exactly like the PC service. Users can access their playlists and music albums, but they have to scroll through their lists randomly using a "Shuffle Play" button. Users can't pick the exact song they want to play right away, and will have to shuffle through their playlists.

"This is the way the next generation will build their music library," said Spotify CEO Daniel Ek. "It's not about purchasing one song or other. it's about adding it to a collection."

Users can access existing playlists or create their lists on the mobile app, he said.

While Spotify, which allows users to pick and choose the songs they want, has proven to be a player in streaming music, it still lags behind leader Pandora, which employs an Internet radio model and can be found on more devices for free. Spotify had previously said it has 24 million active users and 6 million paying subscribers, while Pandora has around triple the amount with 72.4 million active listeners and more than 200 million registered users.

It turns out that the key difference in the business model is what has made it so difficult -- and expensive -- for Spotify to get its service on mobile. Spotify has gotten around it with the shuffle option.

"We're the first and only service to obtain licensing rights to do this," Ek said.

The free service will still continue to get advertisements.

Spotify, meanwhile, also has to look behind it, with Apple making a push to be the dominant streaming music service on its own mobile device. Apple said in October that iTunes Radio had notched 20 million listeners in the five weeks after its launch.

Spotify also announced that Led Zeppelin's catalog will be exclusive to the service.