Any topic is good. Don’t care about format or where it’s published as long as I can access it (substack, random PDF, journal, etc). Looking for deep and rare thought, but essay length for a short reading.
EDIT: Also I am particularly looking for stuff not as much in online or nerd culture.
On music and words - Friedrich Nietzsche (1871)
http://www.gutenberg.org/files/51548/51548-h/51548-h.htm#ON_MUSIC_AND_WORDS