Google Music starts free service to rival Pandora, Spotify

With Apple Music preparing to launch its subscription service next week and Taylor Swift criticizing its royalty payment plans, forcing that tech giant to change course, it's a busy time for the music industry. On Tuesday, Google is going in the opposite direction of Apple's $10-a-month service, launching a free, ad-supported version of its $9.99-a-month Google Play Music in the U.S. The company says it's designed to give artists another way to earn revenue and that the goal is ultimately to bring more people into its subscription service.

Read MoreTaylor Swift criticizes Apple's streaming music service

It's a direct challenge to Pandora, Spotify, smaller start-up Rdio and Apple's iTunes radio, its free streaming service. Google has the advantage of being able to direct people searching for songs to its service; we'll see how much it drives users to its new service as it launches this week on Android and iOS devices, though it is available on the Web as of Monday.

It features the technology of Songza, the playlist start-up Google acquired nearly a year ago. Songza's key focus is playlists customized to your mood and different times of day. In the blog announcing the news it says its team of music experts "craft each station song by song so you don't have to ... with whatever you need music for—from working, to working out, to working it on the dance floor." As with Apple Music's new radio stations, Sonzga used human curators as well as algorithms, an approach implemented in this new service.

Read MoreApple did right thing: Motley Crue's Nikki Sixx

In a dig at Apple, Google stresses that while the service will be free to users, it's absolutely paying artists. This is in reference to the criticism Apple has drawn from Swift and others for originally opting not to pay independent artists for its three-month free trial period for consumers.

Google will allow advertisers in its display ad and video ad systems to target users of Google Music. That gives it access to a massive advertiser base. The question is how many users the new service will draw. (Google won't reveal how many paying subscribers its Google Play Music currently has.)