Final answer:
A beat in music is formed through the alternating pattern of constructive and destructive interference of two slightly different sound wave frequencies, creating rhythmic pulsations known as beats.
Step-by-step explanation:
A beat in music is formed through the interference of two sound waves of slightly different frequencies. When these waves overlap, they periodically reinforce and cancel each other out, leading to the phenomenon of beats. This involves periods of constructive interference where the sound waves align crest to crest or trough to trough, creating louder sounds, and periods of destructive interference where a crest and a trough align, resulting in quieter sounds or silence. This alternating pattern of constructive and destructive interference creates the rhythmic pulsations that we recognize as beats.
The correct answer to the question 'How is a beat formed in music?' is D. Both constructive and destructive inference.
While beat frequency is used in various applications, in music, the phenomenon is essential for creating rhythm and can be perceived when two musical notes with similar but not identical frequencies are played together.
For example, when two tuning forks with slightly different frequencies are struck simultaneously, they will produce beats heard as a fluctuation in the loudness of the resulting sound.