Thanks for trying out the app! You're getting the expected behavior (the instrument is attached to your head), but this is something I'd like to make optional for users. I don't think I'll have time to get to it before the 3D Jam deadline, though. You can see details about all the position/rotation ideas here: https://github.com/aestheticinteractive/Guitar-VR/issues/9
You're welcome. I'm also glad it's the desired behavior because I was starting to think my setup was going weird. The only reason I thought that was because sometimes I'll randomly lose headtracking in my gearVR if there are errors or it's running slow/overheating.
In any case, great work man! It's really something quite cool!