Glad to hear it! Just fyi the next demo update probably won't have any extra levels.
I already have around 22 levels (+ tracks) done for the full version, (however I am having to remake some of those). There is a bassoon in at least a couple of tracks and some strings as well.
If you want to try the playtest version of the game early you can sign up for the mailing list here. I'm hoping to restart the mailing list soon, and I'll send out download links to the latest version, when that's ready~ Probably in a couple of months.