A piezo buzzer is a loudspeaker that uses the piezoelectric effect for generating sound. The initial mechanical motion is created by applying a voltage to a piezo element, and this motion is typically converted into audible sound. Compared to the other speaker designs, piezo buzzers are relatively easy to drive.

Pitch is the quality that makes it possible to judge a sound as "higher" or "lower" in the sense associated with musical melodies. Pitch can be determined only in sounds that have a frequency that is clear and stable enough to distinguish from noise.

In music, a note is a symbol denoting a musical sound.

Notes can represent the pitch and duration of a sound in musical notation. A note can also represent a pitch class.