Twitter Music officially unveiled

Twitter said in a blog post that an app will be available for download from Apple's online store Thursday. A Web version is also expected Thursday. Twitter said the service will eventually be available on Android devices as well.

The service uses information from Twitter chatter to find popular tracks as well as new artists. Users who follow musicians can see what artists those musicians follow and listen to songs by them.

Thursday's announcement about a music service had been expected. "American Idol" host Ryan Seacrest tweeted about it last week. It's called (hash)music, following Twitter's practice of using hashtags to organize tweets around topics.

The music service's debut comes less than three months after the release of a Twitter video app called Vine that distributes six-second clips that can be played in a continuous loop.

The expansion into other forms of media besides text and photos is part of Twitter's effort to make its messaging service even more appealing to its more than 200 million monthly users. More frequent usage of the service creates more opportunities to show ads - the main way that Twitter makes money.

The foray into music could open up a new channel of revenue as well. Apple Inc.'s iTunes pays partners a few cents for every song sale that is a direct result of an online referral. If Twitter's recommendations persuade enough people to buy songs after hearing excerpts, these bounties could add up.

As with many of the other tools that it has added since its inception seven years ago, Twitter bought the technology powering its music app from a startup. In this case, the music app is based on a concept and tools honed by We Are Hunted, which shut down its site for tracking popular music last week.

Twitter, which is based in San Francisco, is winning over advertisers, who typically must package their marketing messages in 140-character characters so that they fit seamlessly into the rest of the rapid-fire chatter flowing through users' feeds.

The company's worldwide ad revenue this year is expected to more than double to $583 million, up from $283 million last year. As a private company, Twitter doesn't disclose details about its financial performance.

That could change soon, though. There is mounting speculation that Twitter is expanding its services and selling ads more aggressively in preparation for an initial public offering stock that could come late this year or early next year. If that were to happen, it would be the hottest technology IPO since Facebook went public nearly a year ago.

Twitter CEO Dick Costolo has repeatedly said that the company isn't under any pressure to go public because it has raised ample financing from investors, including a $400 million injection from venture capitalists in July 2011.