How to Play the Timpani
Where does the player strike the head?
Timpani heads are not struck in the center
The timpani is not struck in the center of the head, but rather close to the rim and towards the player. The wave node runs across the entire head from the center in a straight line, and the vibration's antinode is located at the rim.
Although the pitch of the sound will not change when the head is struck in different places, different harmonics will be produced, which changes timbre. Striking the head about one-third of the radius from the hoop will produce a full tone with orderly vibrations. When the center of the head is struck, the harmonic tones will ring out clearer than the fundamental tone, but without the sustained bass that is associated with the timpani.
The vibration as seen from above when playing at just the right position looks like the illustration shown here.
The white parts contract while the black parts expand, and in the next moment the wave is reversed, with the wave traveling across the entire surface. There are other vibrations in the head which change depending on the tension of the head and location of the strike.