Question

why does tightening the drumhead make pitch go uo

Answer 1

Answer :

If you make the drumhead tighter the pitch goes up, looser and the pitch goes down.

Striking the head of the drum changes its shape and compresses the air inside the shell. The compressed air presses on the bottom head and changes its shape. Then, these changes are transmitted to the drum shell and reflected back, and this action is repeated, creating a vibration. These vibrations of the top and bottom heads create vibrations in the air, which become sound, and eventually, as the head vibrations are dampened, the sound diminishes.

Here, If you make the drumhead tighter the tension in the head of the drum will increases and hence the frequency of the these vibration will increases giving high pitch sound.