Excellent test, Bob. I put the Velocity on zero and all the notes, including the C, sound the same. If I go higher than 1 on Velocity, the C note becomes louder. When this happened today, the first thing I did was to hit the note numerous times fast from soft to very hard and it didn't help. I tried hitting B,C,& Db together a number of times and it still didn't help. I tried using different piano voices - they all come out loud on the C note. The same with sax and other voices.