The days of Twitter being only about 140 characters and viral pictures have gone.

The service has announced that it is teaming up with SoundCloud to deliver audio file tweets that will appear in user’s timelines. Twitter announced on its blog:

With a single tap, the Twitter Audio Card lets you discover and listen to audio directly in your timeline on both iOS and Android devices. Throughout your listening experience, you can dock the Audio Card and keep listening as you continue to browse inside the Twitter app.

The list of audio providers currently using the service includes an impressive number of musicians and luminaries, from @WhiteHouse to @ColdPlay (via @NASA and @ThatKevinSmith).

To date Twitter is restricting the service, but it’s clear from the company’s announcement that the service will be opened up in future. It says:

We’re just beginning to test the Audio Card and plan to make it available to more partners and creators in the future so that many more musical artists and creators will be able to share exclusive, in-the-moment audio to millions of listeners on Twitter.

That’s significant news for any company looking to explore audio content.