I can almost manage “Tu scendi” without any buzzing, but it takes such concentration (and some pressing of strings out of the way) that I’m finding a lot of tension in my hands when I’m done. I’m also finding a lack of dynamic range in the piece due to that tension. I seem to be able to play it at ff or not at all, which isn’t really suitable for a relaxed song like this. My right thumb in particular is annoyingly incompetent, either too soft to hear or practically pulling the string out. 😦
Anyhow, I need to continue to work on this and work on getting it with a minimum of effort and tension. I’m also continuing to work on rolling chords, with more focus on my left hand since that’s where they are 1) easiest and 2) most useful. The right hand will come in the fullness of time.