My "C" Dizi is slightly flat

[jamo]

G'day,
         my "C' Dizi is slightly flat, seperating the two halves slightly does not work, can any please tell me what covering the two holes where a decoration could hang does,
regards Joe.

[davidmdahl]

Pulling out on the joint, in effect making the flute longer, will make the pitch yet flatter. If the joint is all the way in, the only way to raise the pitch is blowing less directly into the embouchure hole. I do this by rolling the embouchure hole away from me a little. Experiment by blowing more directly into the hole and notice the pitch go flatter. Then roll the flute away and notice how the pitch raises.

This is very difficult to explain by words. I hope it makes some sense.

Best wishes,

David