What types of musical instruments would develop underwater?

Question

Water is different from air, and sound waves propagate through water in a different way than they do in air (caused in part by interactions with the bottom of the body of water). For a society living underwater, this could lead to some interesting innovations in music, and musical instruments. For example, currents might help or hurt control of string instruments.

What types of instruments would develop in an underwater society? There a few main groups to focus on:

• Percussion
• Woodwinds
• Brass
• Stringed instruments

Answers don't need to be any more specific than these. I would not expect someone to write a long treatise on underwater performances of the saxophone.

Also, as has been pointed out, it would be incredibly difficult, if not impossible for some of these groups of instruments to be possible. That's fine.

Answer 1

As this answer says, most musical instruments as we know them won't work underwater. You might see something completely new arise, but we should assume that people will first reach for what is easiest. And what's that, for underwater music? Vocalization, as noted in the linked answer.

There's no particular reason to believe that it would sound anything like earthly vocal music, though. Consider these factors:

The scale. The western scale, an octave consisting of 12 half-steps (with variable placement, called temperament) arose from the Pythagorean system, a set of intervals in low ratios (like 3:2) that sound pleasing to the ear. These ratios are easily demonstrated, and were probably derived using, stringed instruments whose sounds travel through air to the human ear. They also occur as harmonic overtones on wind and brass instruments. There's a lot of math theory behind this too, but that's the core.¹

Your people, however, are underwater. They've never heard stringed instruments (unless they came up onto land to do so). Their ideas of what is considered consonant or aesthetic need not have anything to do with these ratios. Sound travels differently through water, the land-based reference instruments are not available, and I'm not even addressing biological differences in ear construction. But you have the opportunity for your underwater music to sound very different, and that can start with a different scale. There's no reason they couldn't have come up with the same scale through math, but you can plausibly change this to make your water-dwellers different.

Melody and rhythm. You've heard whale-song. It, um, doesn't sound like pop music. :-) The sounds are longer and the intervals between "notes" tend to be small (almost "stepwise", were you to impose a scale on that). The latter might be constrained by cetacean vocal cords, but the former is probably in part because sound travels differently through water,² with more echoing. I think this will push music toward being slower-moving; early underwater music might sound a lot like plainchant. (Plainchant also tends away from large-interval jumps; it happens, but most movement is stepwise, and this plus the lack of rhythmic variation contributes to that "somber" sound you associate with it.)

Harmony. I can't prove it, but I think that because of the echos and distortion, from any particular vantage point underwater a note will "linger" longer. This constrains how you can harmonize it if you want the results to be consonant (for local values of "consonant"; this depends on your musicians' biology, for starters).

On land, if you pluck or strike a string and do not interfere with it (damping it, fretting elsewhere along its length, etc), it will ring for some time after the initial note. Those notes are still "in the air" when you (or other instruments) play other notes. As a hammer-dulcimer player I take this into account when deciding what ornaments or harmonies I can get away with; ones that rely more heavily on consonant pitches (e.g. other notes in the current chord) work better than ones that use dissonant notes. On the other hand, there are certain ornaments (like the roll or trill) that work because they use immediately-adjacent notes, so this can go both ways. I suggest that your underwater music will rely mainly on consonances for harmonizing but will also explore the possibilities of well-placed dissonance. Harmony can also use rhythmic variation, so long as its overall shape fits into that long-decay property of underwater music.

---

¹ I admit that I am failing to consider eastern musical scales here. My background is in western music; I don't know a lot about others. My impression is that similar considerations apply to pentatonic and Arabic scales.

² Sound actually travels faster underwater, not slower; the reason it sounds distorted when you're swimming is the echoing, plus any part that travels through air. (Thanks TimB for correcting me.)

Answer 2

Since water is @ 800 times denser than air, musical instruments the way we think of them are not going to happen. Strings and reeds, for example, won't be able to vibrate at the high frequencies that produce musical notes.

We should look at how naturally occurring sounds are made under water. Precussion would work, for example snapping claws or clicking together armoured body parts could evolve into tapping or banging rocks, shells and other hard objects for a percussive sound.

Whales and dolphins use specialized organs to create low and high frequency sounds for communication and echo location, this would be roughly analogous to vocalization. Pods of whales and dolphins communicate to each other using this means, and it is established that individuals have very distinct "voices" and patterns of sound. It might not be too far fetched to suggest pods may eventually learn (or be taught) to harmonize or "sing" in a choral fashion. Extraterrestrial creatures who live underwater might have evolved somewhat differently and be intelligent enough to "sing" in solo, harmonic and choral patterns for various reasons (perhaps Choral "singing" evolved from pods of creatures creating a "wall of sound" to confuse their prey). Due to the high density of water, a performance can be projected for hundreds, if not thousands of kilometres. This might be rather annoying, much like you neighbour playing loud music at all hours of the night.

Since the underwater environment is so different, ideas like music will have to be treated much differently.

Answer 3

The way a piece of music in air sounds is heavily dependent on boundary reflections. Reflections from the mouth of a horn, from a resonant tube, from a piano soundboard, from the body of a stringed instrument, from the environment(a church sounds much different than a forest, anechoic studio, or a wide open field). As such, we have developed a wide variety of instruments to exploit this property. I believe this would not be so for underwater instruments.

Because air has little mass and is highly compressible, it effectively(low distortion) transmits low energy sound without creating many reflections of its own. But its compressible nature is less efficient(slow). We generally assume that any sound we hear is close to us, certainly closer than the horizon. The resonant frequency of air is not a significant factor.

Water has higher mass and is not very compressible at all. It transmits sound efficiently(fast) because the molecules are in closer contact, but not as effectively(high distortion) because its high mass creates a pseudo boundary reflection at every point along the way. Being flooded with so many uncontrollable reflections from the transmission media, the nuanced reflections of a finely crafted instrument would be lost in the noise. The only signals that would transmit clearly are near water's resonant frequency.

Therefore, I believe there would be a very small variety of underwater instruments. And most would produce sounds near a harmonic of water's resonant frequency. The composition of underwater music would have many of the same practical constraints as the production of church music. Slow smooth progressions from note to note avoiding unpleasant chaotic step reflections. The frequency content of the original signal(as opposed to instrument design) would become much more important in determining what the listener actually hears. Yet, what the listener hears underwater will be vastly different from the original signal at the instrument.

I expect that most underwater instruments would have tone compensation controls based on water temperature, pressure, and salinity.

Answer 4

The reason for our scale and chords are not (just) related to strings. If you look at the chords drawn as waveforms you can see that simple rational numbers make new simple repeating patterns on the same time scale as any timber. I've seen the 5 note scale derived using whistles, not strings.

These are real fundamental effects that are independent of how our ears work, other than that they work suitibly to discern real natural sounds.

The auditory sense of a marine mammal or other aquatic creature might be built to cope with the increased dispursion of sounds travelling long distances in the ocean. This could cause them to hear certain sounds as “near” or “far” versions of the same source sound. That can go into their music! Perhaps time shifts for different frequencies will be a basic musical element and present in the notation.

As for how to make sound, as I recall the cetation anatomy, one nostrel is the blowhole and the other recirculates through internal “lips”. The sound is made by vibrating a reed in air (a small quantity of air) and then impedance matching to the water.

As for real instruments to look at, I recall a horn like thing made to play with water passing through it, and various items made by Peter Schickele and played in a tank on stage.

Answer 5

Perhaps instruments making infra sounds from more slowly vibrating things? Fishes recognize such vibrations and might react on intervalls and chords of tonic, dominant and octave? This kind of "music" is a perfect analogy.

Answer 6

Woodwind and brass instruments rely upon the speed of sound in the medium within which they reside; since the speed of sound in water is much faster than in air, such instruments would need to be twice as long to yield the same frequency in water as in air. Further, the portion of the instrument that converts changes in velocity to changes in pressure (e.g. the reed, embouchure, etc.) would need to be sensitive to smaller changes in velocity than would be typical in an instrument used in air, since water's change in velocity with respect to pressure will be smaller than that of air. Alternatively, it might be possible for instruments to use variations in pressure to cyclically induce and suppress cavitation in an air-powered instrument, but I'm not sure at what frequency ranges that would be effective.

For things like stringed instruments and percussion, I think the key to success would be to have vibrating members within a trapped gaseous cavity, arranged in such a fashion that vibrations could be loosely coupled to the outside of the cavity which would in turn transfer them to the water.