@patrickrhone This is such a fun thread! Beyond specific songs about the music industry, there’s Zappa’s We’re Only In It For The Money and Fillmore East June 1971 albums. And I think we should also call out the “Taylor’s Versions” re-recordings that Taylor Swift has been releasing over the last few years; they’re a sort of meta-commentary on the rapacious industry and its relentless exploitation of artists.
We’ve been focusing on music, but there is just as much evidence for your observation in writing and visual art, too, of course. Many fat anthologies could be amassed, composed only of poems about writing poems. Whole libraries of novels about novelists.
In the visual arts, I would, off the top of my head, call out Francesca Woodman. Also Francis Bacon. And MC Escher did a number of self-portraits. A lot of Rembrandt’s portraits are actually self-portraits. Also, Las Meninas.