Neocities.org
for me my script works, at least on the /rei page, on firefox as well as edge after clicking on a random part of the site (not the link). could you show me your Console log? the script is not in the source for /hate for example, if you mean that. btw i really like the style of the page!
It doesn't work because on some pages embeds are being used instead of audio: those can't be played via JS as far as I'm aware. Also, your script can be condensed into this: https://pastebin.com/1RXMrAfg (Isn't JavaScript crazy?)
Oh very cool. I missed those embeds, i thought all pages used audio elements.