Are C♯ and D♭ same? Interval & Octave explained: Music & law of frequencies

Octave is derived from a word that means eight. Why are there twelve notes? Why are there no black keys between E and F, and between B and C? Why is there only a single key for both sharp and flat? Why does the concept exist?
These questions will be answered in this video.

Become a member: https://youtube.com/Bisqwit/join

My links:
Twitter: https://twitter.com/RealBisqwit
Liberapay: https://liberapay.com/Bisqwit
Steady: https://steadyhq.com/en/bisqwit
Patreon: https://patreon.com/Bisqwit (Other options at https://bisqwit.iki.fi/donate.html)
Twitch: https://twitch.tv/RealBisqwit
Homepage: https://iki.fi/bisqwit/

Some footage is generated with Wav2Lip. I also used https://hotpot.ai/colorize-picture .

Видео Are C♯ and D♭ same? Interval & Octave explained: Music & law of frequencies канала Bisqwit