WATCH VIDEO. YouTube is launching a music subscription service next week, YouTube Music Key.

The service will cost $9.99 a month for ad-free music, plus music videos, and the ability to listen offline as well as online.

Itís starting as an invite-only beta service: people who are invited are offered six months free, followed by a promotional lifetime price of $6.99 per month.

YouTube Music Key subscribers will also get access to Google Play Music, which also costs $9.99 and has access to 30 million songs, so this is effectively an extra service for those Google Play Music subscribers.

Now subscribers will get access to many more music videos ó a natural area of strength for YouTube. The company is also rolling out a recommendation service based on your habits listening across both Google Play and YouTube Music Key.