Last.fmis introducing a charge for the streaming functions in its mobile app.

We had a chat with Matthew Hawn of Last.fm to find out what the change means.

The various versions of the mobile app stream a personalised music feed of your favourite music and related recommendations.

Up until now, this has been free, but it will soon be chargeable.

The ad-free subscription costs 3.

The radio service will become a paid feature on 15 February.

The Web and desktop versions of the radio will still be free.

It will also be free on Xbox Live and Windows Phone 7 phones.

Hawn emphasises that Last.fm’s focus is discovering and keeping track of music rather than streaming or listening.

He describes the service as “musical check-in”, more likeTwitterorFoursquarethan radio or streaming services likeSpotify.

We’d definitely like to see what that would look like.

Last.fm is owned by CBS Interactive, the same company that owns CNET UK.

So now you know.