I've been playing for a while.. it seems that underneath the lip plate there has been some bacteria/dirty stuff acumulating. You can see it if you flip over the headjoint. I wonder if theres a way to clean it. Its in a small area so.. I have no idea. HELP PLease
It's probably just tarnish, no big deal. I would be very careful if you try to clean under it, because it is possible to accidently make your lip plate fall off.