Apple's Ping - described at its September launch as the social network of music - has now been integrated into Twitter.
Users can now incorporate Ping activity, song previews and links to purchase and download music from the iTunes Store directly into theirtweets.
"On Ping you can easily link to your Twitter account to instantly find Ping users among the people you already follow on Twitter," says the Twitter blog.
"Once you’ve linked the accounts, whenever you Post, Like, Review, or tell your friends why you purchased a song or album on Ping, this activity will also be tweeted to your Twitter followers – complete with playable song previews and links to purchase and download music from iTunes."
Clicking on a tweet that's sent via Ping, or whcih contains an iTunes link, will throw up the song or album in Twitter’s details pane, along with the ability to listen to song previews from iTunes.
iTunes song previews are available in the 23 countries where the iTunes Store offers music.
Apple's believed to have talked to Facebook about a similar tie-up, but found Facebook's terms too much to swallow. When Ping launched in September, Steve Jobs said Facebook had prevented Ping from integrating with it. Apple and Twitter haven't disclosed financial details of their deal.
The deal helps Apple counter one of the most strident criticisms of Ping - that for a social networking tool, it's simply not very social. But it also emphasizes just how Apple sees the service - as a way of getting people to buy more music from iTunes.