Twitter now allows you to tweet to followers about the music you like – or maybe don’t.

The Web-based social messaging service unveiled Thursday a mobile-music application that will let its users play and share songs from services including Apple Inc.’s iTunes.

The app is available for Apple today and will later be added for devices running Google Inc.’s Android software, Twitter said in a blog post. In addition to iTunes, it will work with streaming music from Rdio Inc. and Spotify Ltd.

Twitter is going beyond 140-character messages as it vies with social-networking rivals to get users to spend more time on its site. The San Francisco-based company released a video app in January. Adding music would give record companies a way to promote new tracks by taking advantage of Twitter’s word-of- mouth network.

Internet users are increasingly relying on social networks to find new music as streaming services such as Spotify and Rdio let subscribers share songs and playlists through Facebook Inc. The dominant social network recently updated its news feed to make it easier to discover music.

Twitter’s service, called #music, will be available starting today in the U.S., Canada, the U.K., Ireland, Australia and New Zealand. Users can download it from Apple’s App Store and from Twitter’s website.

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 of 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.

(The Associated Press and Bloomberg contributed to this report.)