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 Modartt for gifting me a copy of their amazing Pianoteq software. Find out more here: Thank you to Fred Scalliet for adding French subtitles to this video! Sources: Gamelan Music: 12Tone talking 12TET: Where does the 12-tone scale come from: Audio Spectrum (AdminOfThisSite): Perception of Octaves: Playable Harmonic Series: Octave circularity in the auditory brain: