My daughter gave me a used clarinet since I told her I played as a kid. The problem is when I play the "A" fingering (440 bps) I get a "G" and when I play an open "G", I get an "F" and so on. What am I missing? The clarinet is a B flat, which is what I played years ago, but I don't remember this happening. Is there a way I could correct this such as with a shorter barrel, or does it need correcting?