I do, yes. I won't call it a hobby because I don’t create anything, I'm just a mindless rabid stupid cunt of a consoomer who doesn't know how to differentiate his ass from a hole on the fucking ground, but I do spend a lot of time listening to music. I've spent a lot of money on audio equipment.

Even so, if you wanted to bring up time signatures, microtonality or something like math rock… I'm aware of those, but I still think the only thing that matters is that they're tools meant to allow you to express a certain message in the most appropriate ways, not so much an end in themselves.

Sounds a damn good hobby to me.

I don't think hobby requires building anything. Spending time actively engaged is enough. One can enjoy mathematics the way one enjoys listening to music.

On the other hand if you do want to make something, and you happen to know related math then suddenly you can use it.

For example, https://news.ycombinator.com/item?id=47112418

Building these are neither my hobby, not did I learn the relevant math for the exclusive purpose of making it. But once you acquire a few math razors you start seeing inviting fluffy yaks that were invisible before.

> but I do spend a lot of time listening to music. I've spent a lot of money on audio equipment.

This is a great domain to motivate oneself to delve deeper into Mathematics. For example;

1) What parameters do you look at in audio equipment before you buy?

2) Somebody is trying to sell you "Hi-Res" music and equipment; Are they worth the money? Why? Why Not?

All of the above need mathematics to comprehend at even a basic level. There are both complicated objective (physics/mathematics) and subjective (our auditory system) parameters to understand eg. logarithms, harmonic series, frequency modulation, tuning, impedance, human hearing frequency range and sensitivity etc.

Having some mathematical idea of the above not only saves you money but also helps you enjoy music "optimally".

References:

Sound: A Very Short Introduction by Mike Goldsmith (also see his other related book on Waves) - https://global.oup.com/academic/product/sound-9780198708445?...

The Science of Musical Sound by John R. Pierce. An old classic (also checkout his other books on Waves, Signals and Information Theory). They are all written in a semi-technical and clear manner for the general audience. - https://en.wikipedia.org/wiki/John_R._Pierce