When David Bowie passed away last month, I spent an inordinate amount of time listening to his standout song, “Starman.” I was listening to it when I found out he died; this coincidence was particularly devastating.

What was it about this four-minute track, half-sublime, half-somber, that was able to elicit such a strong reaction from an ordinary listener like me? Was it Bowie’s cavernous 12-string acoustic that sounded like it was being played in a grotto, or Mick Ronson’s piercing Les Paul that soared to glorious glam-rock heights at the conclusion?

When we talk about music, we are talking about sound. But not any sound will do—music, we might say, is a deliberate arrangement of sounds meant to aesthetically impact a listener.

In terms of physics, this isn’t so complicated. Virtually all displacements of physical objects produce sound. Your fingers moving across a surface produce sound, even if it’s only minute. The cannons that stood against Napoleon’s Grande Armée at Borodino in 1812 produced sound when launching cannonballs into the air; so did the ones Tchaikovsky used in his rousing 1812 Overture.

The main difference between the battlefield cannons that Napoleon’s army faced and the ones that were fired off while Tchaikovsky himself conducted an orchestra at the dedication of Carnegie Hall in 1891 is the intention with which they were fired. In the former case, they were instruments of war meant to slay enemies. In the latter case, they were sonic blasts operating within the context of a highly-structured series of sounds.

I’ve written before about how music can affect a listener’s perception of time. I now want to turn my attention to an examination of these sounds we call “music” in and of themselves.

Are these structured pieces of sound subjective or objective? Will they always affect a listener the same way? And perhaps most importantly, is it possible to conceive of music without humans to create or listen to these sounds?

This is where a physics of music ends, and a metaphysics begins.

First off, I want to do away with the immediate temptation to call music subjective.

What I mean by that is not so much that one listener isn’t free to prefer a given piece of music over another as a matter of taste. What I’m trying to say is that not any sound can be considered music. A listener can’t just refer to the speeding of a train or the sound of a page turning in a book as music.

That’s because music by its very nature entails a specific structure of sounds. Which is not to say that music can’t be dissonant—we should still acknowledge Miles Davis’ “Spanish Key” or The Velvet Underground’s “The Black Angel’s Death Song” as authentic pieces of music. Whether we like those dissonant pieces is another matter.

In any case, there’s method to the madness. There’s instrumentation and a particular layering of sounds meant to affect the listener in music that isn’t present with ordinary sounds resulting from physical displacement.

The philosopher-mathematician Pythagoras, whose theorem on right triangles you most likely studied in high school, was the first to discover that musical scales follow a sequence of numerical ratios. Depending on the tension on a string, Pythagoras found it was possible to establish precise ratios for the distances between notes and that identical notes vibrate at the same frequency.

For further illustration, I can point out how my personal favorite chord, A Major 7th, always consists of the notes A, C#, E and G#. If those notes are played in unison, a listener has no place to not refer to it as an A Major 7th chord. Independently of how an observer hears it, a chord either is or is not an A Major 7th because the notes it consists of must vibrate at a specific frequency.

Enough said then for the basic objectivity of music per se. There’s a particular numerical quantity to each note in a musical scale independent of an observer’s perception. That we’re still studying the intricacies thereof today says something about the very independent nature of sound.

As for whether the same piece of music can affect listeners in different ways—I think that’s pretty self-evident. You may love Drake’s “Hotline Bling.” I could take it or leave it, myself.

I don’t think it’s as obvious, however, whether what we call music would exist without people to create or listen to it.

On the one hand, the essential component of music—sound—I think clearly would exist if there were no humans to hear it. The drizzle of raindrops on the ground or the roaring of thunder in the sky would probably continue to produce sound, even if none of us were around to hear it.

On the other hand, if music is a purposefully layered structure of sound meant to move a listener as I’ve argued, I’m not so sure.

Neither “Starman” nor “Hotline Bling” would exist without humans; that’s certain. But then again, some people listen to the sound of thunderstorms or the crashing of ocean waves on a shore as “music of nature.”

I’ll leave this question open ended, but here’s some food for thought: Pythagoras believed in a theory called “Music of the Spheres,” according to which each planet in the solar system emitted a unique sound in the course of its revolution, with tonal relations in the distances between the Earth and the moon, the moon and Mercury, Venus and the Sun and so on.

Feel free to dismiss Pythagoras’ astronomical theory as outdated nonsense.

Even so, you still had to study his take on right triangles over 2,500 years later.

Featured Photo Credit: Aladdin Sane [Belgian], after David Bowie’s Aladdin Sane (1973). Original artwork by Duffy (photography and design) and Celia Philo (design) for the Kitchen Tool Shop. Make-up applied by Pierre Laroche. (Photo courtesy of Marc Wathieu via Flickr)

Horus Alas is senior philosophy major and can be reached at heliocentricnonchalance@gmail.com.