Why are melodies typically played or sung by high voices or instruments in an ensemble?

Question

In the pop idiom, there appears to be a significant pattern of successful pop songs having high-pitched male vocals.

Bruno Mars, Michael Jackson, almost all rock songs (FOB, All American Rejects, Red Jumpsuit Apparatus, etc).

Put any of those vocals 1 octave down and it wouldn't be as catchy.

Is there something about the way humans naturally perceive sound that contributes to this pattern?

As commented by @Lee White,

While the perception is indeed subjective (not everybody prefers high voices), this question is about a very clear pattern that may have a scientific explanation. You could ask the same question about instruments: why is the first part generally played by the soprano violins and not by the double basses? Why are there so many more guitar solos than bass guitar solos?

Answer 1

You're right, this is pretty subjective. Loads of great songs use low voices. I don't think higher voices are necessarily "more pleasant" to listen to.

But, you may be right that pop and rock songs use high voices a lot; this is likely to be effective because it raises the melody line away from the pitch of the other instruments, making it easier to hear. Also, when singers use the top part of their range, the extra effort (strain?) adds excitement and emotion to the performance. (This is particularly true in rock and metal.)

Interestingly, there has been research suggesting that we "hear" male and female voices differently. I have not read enough about this to know whether this is simply due to the difference in pitch. For example, this article (which refers to research published in this journal) asserts that men hear male and female voices differently.

When it comes to processing a woman’s voice, they [men] use the more complex auditory part of the brain that processes music [my emphasis], not human voices. But the guys in the study could easily hear and understand other mens voices as speech because that uses a simpler brain mechanism at the back of the brain.

(So, I guess this begs the question: do at least half of us hear higher voices as being more musical? I would need to read more of the research to offer my own opinion.)

As I say, I can't say whether this affects our response to the pitch of vocal melodies in songs (or if it even helps to answer your question!), but it is pretty interesting, I think...

Answer 2

High frequencies are more intense than deep frequencies. A bass, for example, can be boosted in an audio track without great differences for the ear. Turn up the high frequencies and your track will start to screech. The human ear notices high pitched notes better than deeper ones, which explains why the catchy part of songs are often sung higher than a normal verse. The frequencies a human hears best are somewhere between 1,000 Hz to 5,000 Hz, which are quite high tones.

However, there is a difference between loudness and intensity: While a bass solo could be much louder than a guitar solo, you would still hear the guitar better, because of the high notes, which sound more intense.

This behaviour varies from genre to genre. While pop music often focuses on vocals and the "main hook", other styles (metal as an example, which focuses more on deeper guitars) can also try to sound more stable/sturdy by using deeper vocals and might want to leave some room for other instruments (which you can hear better if the lead vocals are deeper).

However, it also depends on the vocal range and on the stylistic choices of every musician: Bruno Mars writes a lot of love songs and also gives his songs a romantic/happy/feminine touch. His songs would be less appealing love songs if he had a deeper voice.

Briefly said, our ears prefer higher notes because we hear them better and can notice them far more quickly, instead of focusing on a bass solo which the average ear almost cannot hear.

Answer 3

There is a hypothesis that music evolved from motherese. If this is true, it would make sense that popular melodies are high pitched, as motherese uses exaggerated high pitch.