Normally, if you want to play music or other audio on a microcontroller, you need to get yourself a DAC. Or at least, that’s the easiest way to go about it and the one most likely to get you good, intelligible audio. You don’t have to go that way, though, as [antirez] demonstrates.
This is a companion discussion topic for the original entry at https://hackaday.com/2024/03/12/playing-audio-on-the-pi-pico-with-no-dac-to-speak-of/