My Pierret alto was victim to numerous leaks - one reason it played so poorly. I took it to an expert tech who fixed all the leaks right there. However, I was shocked to see that he was bending the keys! Ouch! He was bending the keys so that light wouldn't shine through when he closed them. Is this standard practice for fixing leaks? I'm happy to say that it plays much, much better now. There was a leak on practically every tone hole.