Which of the following is a characteristic of a 'loop' in music?

A loop in music is indeed a sound that is often manipulated, making it a versatile element in musical composition. In music production, loops can consist of pre-recorded segments of sound that can be repeated and layered to create a rhythm or melody. This manipulation can occur in various ways, such as changing the pitch, tempo, or adding effects like reverb or distortion.

While other options describe possible misconceptions—like suggesting a loop can only be used once, is static, or does not repeat—these do not accurately represent the nature of a loop. In practice, loops are key components that enhance creativity and structure within compositions, allowing for dynamic and engaging musical experiences.