This effect still happens with cheap battery-powered cat toys that chirp. Some are rechargeable... others are not, and keep squawking pixelated noises of various pitches for years on end. Ask me how I know.

Good for circuit bending! I miss the times when just a resistor or bat voltage controlled the chips clock cycle without insta-crash

Doubly so if they were motorized toys, so when the motors kicked in, the battery voltage would droop and make the pitch shift even more...

It is not uncommon to for some guitarists to use partially depleted batteries to power certain effect pedals, especially fuzz pedals. People can get particular about tracking down specific brands of carbon-zinc type batteries that are perceived to have preferred discharge characteristics. And there are “battery sag simulator” pedals.

https://danelectro.com/product/1960s-vintage-battery/

https://jhspedals.info/products/volture?srsltid=AU7gw4VF4W_4...

Bass players too!

At least that's the story I've read online a few times about the bass sound on Sir Psycho Sexy having to do with the dying battery on the pedal.

And, of course, just a little bit before DSP and simulators become available (or feasible for mainstream availability), those of us who were playing as teenagers in the 90s often got weird sounds on account of trying to juice the last bit of the batteries in our pedals. I love it that some among the current generation of kids like to simulate tape hiss, dying batteries, and other things we'd suffer then :)