One of the key new apps for the Nokia Lumia 800 is Nokia Music, a twist of Microsoft’s Music hub and Zune offering. But what is it all about?

Nokia music will be a free app installed as standard on the Nokia Lumia 800 and only be available to Nokia users.

The app consists of a number of features and is, in reality, the rebirth of the company’s failed Comes With Music offering of yesteryear.

The key selling point however is a feature called MixRadio, a free, global, mobile music-streaming application that delivers hundreds of channels of locally-relevant music to be streamed or saved for offline listening.

Offline listening is restricted, but not overly so. Users will be able to download up to 4 stations and up to 14.5 hours of music at any one time (that’s around 200 tracks in total). Music is downloaded in AAC+.

There will be 100 channels according to genre and each one of them contains 50 songs which are refreshed once a week.

If you just want to listen to new releases, there’s a channel for that.

At launch Nokia will curate that service, and the company has already said that it will be looking to key music influencers and artists to create lists. Expect everyone from the UK Top 40 to Lady Gaga to want to get involved.

Nokia has also said that it plans to offer users the chance to create personalized channels from a global catalogue of millions of tracks in an update scheduled for a later date in a similar vein to how Spotify works. (Spotify you had better get your skates on for that WP7 launch you promised in 2010).

To help it create those personalised tracks the app will also, via a website on your PC, scan your music collection and tell you what kind of music you have – be in rock, pop, jazz, etc – and then suggest further music you should listen to based on your profile.

According to the lead exec on the Nokia Music app, Mark Wheatley, it takes minutes to scan your tracks:

“It took just three minutes to scan my 95,000 track collection,” he told the Windows Phone blog from Microsoft when describing the new feature.

But it’s not just MixRadio that music fans should look forward to. Also integrated in Nokia Music is Gigfinder, providing the ability to search for live local music for a that is on nearby and then buy tickets from your phone there and then.

Those are the more exciting features of the new app, however the Nokia Music Windows Phone 7 app also lets you buy music from Nokia’s 15m track collection, as well as stream Internet radio and listen to your own music.

The Nokia Music app will be integrated into the Zune experience. Users will be able to use the Zune controls on the phone to control the music they listen to in Nokia Music and see the tracks they’ve been listening to in the Zune app as well.

Nokia Music will be available on the Nokia Lumia 800 when it launches on 16 November 2011, and the Nokia Lumia 710 when it launches early 2012.