Why do drums or drum kits have an indefinite pitch?

Drums or drum kits have an indefinite pitch because the sound they produce is not a pure tone. When you strike a drum, the sound produced is a complex mixture of frequencies, including the fundamental frequency and its harmonics. These frequencies decay at different rates, resulting in a sound that does not have a clearly defined pitch.

Additionally, the pitch of a drum can change depending on how it is played. For example, playing a drum with different sticks or beaters, or striking the drum in different areas, can change the sound produced and affect its pitch.

Unlike musical instruments like pianos or guitars, which produce specific and fixed pitches, drums and other percussion instruments produce sounds that are more transient in nature and have an indefinite pitch.