The All Access service, linked to Google Play for Android and costing $9.99 a month, puts Google in direct competition with a number of streaming competitors, a group that could include Apple, which is rumored to soon offer a music streaming service of its own, CNET reported.
All Access was unveiled at the Google I/O developers' conference in San Francisco.
"This is radio without rules," Google engineering director Chris Yerga told developers attending the conference.
All Access will offer an "Explore" feature, a "guided way for you to browse millions of tracks," he said.
There will be 22 "top-level genres," with "more to dive into," Yerga said, with playlists curated by Google music editors.
"Anything you see, you can immediately start playing."
Google didn't announce which record labels it had on board, although there have been rumors it has signed licensing agreements with Universal Music Group and Sony Music Entertainment.
Benedict Cumberbatch's dramatic reading of R. Kelly lyrics is just what you need
Exploding whale video goes viral on Internet