Which statement about sound composition is accurate?

The accurate statement about sound composition is that almost all sound contains multiple frequencies. This is due to the fact that most sound waves are complex waves, which consist of a fundamental frequency along with various overtones or harmonics. These additional frequencies contribute to the richness and timbre of the sound we hear, allowing us to distinguish different sounds even if they are at the same pitch.

For example, when a musical instrument plays a note, it typically produces not just the fundamental frequency (which corresponds to the pitch we perceive) but also several harmonics that are integer multiples of that fundamental frequency. This complexity is what allows us to differentiate between the sounds of different instruments, even when they are playing the same note.

In contrast, the other statements are not accurate due to the general nature of sound. Sound does not limit itself to a single frequency; human ears are capable of processing a range of frequencies simultaneously, and all sound, especially at lower frequencies, can have overtones that enhance its quality. Thus, the characteristics of sound composition reflect a rich tapestry of frequencies rather than a simplistic one-frequency approach.