The UI (or should I say UX now?) is 90% complete (for this iteration that is) as the image below shows. There are a few bug fixes left to complete, plus I'd like to to some moderate re-factoring of both the 'business' logic and the XAML.
I'll post some of the more interesting aspects of the project in later posts and either make the source available from here or I might look at uploading to Codeplex et al so others can go ahead and take it forward if it's found to be interesting. There also be a 'live' version available. I'll be using it personally to try out different keys & progressions for future compositions.