Sound Is Universal. Theory, on the Other Hand…
DLT, fellow music lover, asks: “Is it true that musical notes and scales are universal? Is all the music that’s ever been (or will ever be) created using the same set of notes? How can this be?”
Maybe...but not necessarily. That's because we're really talking about two different things:
The physics of sound—which are universal, as they are responsible for all sound, everywhere.
Music theory, which attempts to organize sound into systems of notes, scales, chords, etc.—which can vary by culture.
Yes, math rules. But somehow I get the feeling your question has more to do with #2, music theory—which is a slightly thornier topic. My good friend Aaron Washington—who attended music school, has written for and conducted orchestras, and is a multi-instrumentalist and budding media composer—provided me this paraphrased explanation:
"The notes we play are universal in the sense that music from around the world uses those same notes; because after all, sound is just a bunch of audible wavelengths. Even so, some cultures may use some notes more than others, or not at all—although that isn't to say that any notes are hidden or unavailable to all cultures. But as I do not know how a particular culture may teach its own music (theory), what I interpret as a 'G' note may be something totally different to them."
At the end of the day, Aaron puts it succinctly: "Sound is universal...while music theory is not."
For further consideration…
Trust me, once you wander too far down either rabbithole—the "physics of sound" or "music theory"—the explanations get complicated, real quick. Even so, I would be remiss without leaving you just a couple other quotes from online articles, to feed your curiousity:
“The twelve-tone system is not a global standard; many non-Western cultures use different tonal systems. However, some intervals – namely the octave – are present in all musical cultures. The structure, significance, and emotional interpretation of intervals within the octave depends on the culture.” https://www.lessonface.com/content/why-does-our-musical-alphabet-have-twelve-tones
“The idea behind twelve [notes] is to build up a collection of notes using just one ratio. The advantage to doing so is that it allows a uniformity that makes modulating between keys possible.” https://www.math.uwaterloo.ca/~mrubinst/tuning/12.html
As a bonus—and because I wouldn't be me if I didn't mention this—there is also a YouTube video by musician Adam Neely, which talks about Western "music theory" from a racial perspective. Whaaat? For our purposes, I have no need to get into those politics. (Fair game for a future article, though.) Even so, it's pretty eye-opening, if you can last all 45 minutes. https://youtu.be/Kr3quGh7pJA
Conclusion…
Although the "theory" part of music is not universal—sorry to burst your bubble there—it's still vital. If music can be considered a language, then music theory is how each culture notates, preserves, passes on, and helps utilize that language for multiple purposes—including professional, academic, entertainment, and otherwise.
Thanks again for the knowledgeable assist from Aaron Washington, my brother in music. Aaron's talents also extend to graphic design, web development, and video editing. https://aaronjwashington.com