It’s also worth mentioning that these are very western ideas. Lots of other cultures derive alternative structures not based around 12 half steps to an octave and so on.
The example I'm most familiar with is Carnatic and Hindustani music, where there are theoretically 22 tones per octave, and in fact the tones in most cases actually cover a range of frequencies rather than a single one. Nevertheless, the most common and most popular music from those traditions tends to only use about 7 tones per octave (equivalent to a western "scale"), and they still have a very central for tone ratios like 3/2.