Final answer:
The simultaneous sounding of three or more pitches in music produces harmony. Beat frequencies are also produced when different pitches are played simultaneously, adding a unique texture to the music.
Step-by-step explanation:
The simultaneous sounding of three or more pitches in music produces harmony. Harmony refers to the combination of multiple pitches played together to create a pleasing and balanced sound. When different pitches are played simultaneously, they interact with each other in various ways, resulting in different types of harmonies. For example, when three pitches with slightly different frequencies are played together, they produce beat frequencies, which are periodic fluctuations in the volume of the sound. These beat frequencies add a unique texture and depth to the music.