After months of trickling information, YouTube's subscription service for its videos and music has finally started to take shape. Dubbed YouTube Music Key, the service will launch next week as an invite-only beta to access high quality audio and ad-free videos.

Leaks earlier this year suggested that YouTube Music Key would give access to a 20-million-song database, a radio-style streaming service called YouTube Mix, and ad-free, offline playback of music videos. "Starting today, you’ll see a new home just for music on your YouTube app for Android, iOS and on YouTube.com that shows your favorite music videos, recommended music playlists based on what you’re into and playlists of trending music across YouTube," states Google's blog post on the subject.

Consistent with the rumors, subscriptions to YouTube Music key will also give customers access to the entire Google Play Music database, which includes 30 million songs. In addition to allowing ad-free offline play, YouTube Music Key subscribers will also be able to play videos on a mobile phone even if they lock the screen or start using another app, actions that normally kill playback.

The beta opening next week will be invite-only and run for six months. When that period ends, beta users will be offered the option to continue subscribing to YouTube Music Key for a discounted $7.99 per month. All other new users will get access to the service when the beta ends at $9.99 per month.