Why Does Music Only Use 12 Different Notes?

Why does Western music divide the octave into 12 different notes? Why not 13, or 19 or 24 notes? For such a simple sounding question, the answer is actually a tangle of history, physics and human preference. Get ready for some serious music theory!

Thank you to Fred Scalliet for adding French subtitles to this video!

Sources:

An extra special thanks goes to Vidad Flowers, Austin Russell, Christopher Ryan, Bruce Mount, Toot & Paul Peijzel, the channel’s Patreon saints! 😇

[DavidBennettPiano]

❗ CORRECTION: At 5:41, it should read "For Major Sixth multiply by 1.666, and Minor Sixth multiply by 1.6" but I got them the wrong way around 😅 Thanks to Hans Bakker for spotting this 👍

[amyshaw]

Im not "playing the violin badly", I'm just experimenting with microtonality

[loka]

Maybe more will be added in the next update.

[excellentmike]

I'm a non-musician trying to understand what music is. I had to look at maybe 6 or 7 videos on "basic music theory" before I found one that explained the plain fundamental facts about music, musical notes and intervals so clearly explained in this video. Well done. Thank you.

[CatServant]

My late wife was the musician in my family. She played multiple instruments. She knew all about temperament and tonality. I, on the other hand, was only trained in vocal music, so the intervals are the important thing. It’s great to see both points of view in one video. Also, being a retired engineer, I appreciate the mathematics.

[thomas.thomas]

music in school: hella boring
music when you voluntarily are interested in it and research music theory on your own: cool and interesting

[tuhmater]

“There are usually only 12 notes”

Trombones and fretless string instruments:
*they will never understand our power*

[MrGeeyess]

60 years ago I worked for a company that pioneered electonically produced tones. The organs were tuned on 12 PCBs using an oscilloscope to equal temperament. When done, I was charged with 'tweaking' the potentiometers on each PCB to make them sound 'right'. We never discovered the science behind this phenomenen. This video explains this perfectly. Thank You.

[cateclism]

I have a Master's degree in Music Theory, and you just explained this subject so much better than I could have!

[karhukivi]

This should be taught in schools as a linked maths-music lesson to show students how maths is embedded in many aspects of life. Excellent explanation of the 12-tone octave - thanks!

[clemsonalum]

I'm really bad with music and been trying for DECADES to get it explained and most music people can't explain it well, this was a massive help.

[DonOctave]

Thanks for explaining this. Your explanation about tempering helped me to understand something my 7th grade music teacher said 50 years ago. He told us that in Bach's time the harpsichord would need to be retuned every time the performer wanted to play a piece in a different key, and that if we were to hear a piece played back then, it would sound strange to our ears. Now, I understand why.

[GurgMaster]

Weird but as a mathematician and an average guitarist, this has made a lot of music make a lot more sense to me! Thank you

[chipcurry]

I’ve been playing music professionally for over 50 years, and this is the first time I’ve completely understood this.

[howimettheopera]

As a musician who also makes videos, I know how hard it is to try to organize complex information in a clear manner. You´ve absolutely nailed this, great job!

[thezachmarsh]

Ever since I opened myself up to quartertones, I've discovered harmonies and intervals that are some of the most beautiful things I've ever heard.

[cloerenjackson]

This is my favourite music theory channel. Many of the others are just "Look at this mad chord progression Tool used" but this one is made for people who really want to learn music theory and the topics are ones which can quickly be applied practically to compositional or harmonic ideas. It's designed to be something you can use rather than something to make you go "wow". It's very well organised and presented too, again to be followed and understood, rather than to make you go "wow".

[DannyTaddei]

I’m 58 and started playing piano at age 2. I make my living from music. I studied my entire life and though I knew the basics of this I have never understood it as I do now. Your videos are superb and I always learn something from them. Thank you.

[Divedown_]

Hardly anyone explains music topics as good as you. And young you are. Should have 10Msubs!

[TheMarkSpurs]

Thank you David for making this video. I had struggled to understand the why behind the chosen notes along with making the connections to the tuning and the various note names that are thrown around. This info was just what I needed to tie it all together. Well done and only 17 minutes long :)
Cheers.