Last month, I came across a professor on Twitter asking if one of their grad students should be allowed to write a paper on an album instead of a book of poetry. The resulting replies are mostly affirmative; quite a few responders use Kendrick Lamar's Pulitzer as reasoning. I don't agree with citing the Pulitzer, but I agree with allowing the substitution.
Music is poetry. It uses rhyme, repetition, and many of the other mechanics deployed in verse. Bob Dylan won The Nobel Prize for poetry as a musician (my thoughts here). An album is just another form of poetry collection.
A few people pointed out the professor stated it had to be a book, but what constitutes a book? An ebook isn't on paper. An audiobook can be on CD, cassette, or streaming service. As technology changes, our exact definition for "book" becomes a bit more nebulous. Just because the delivery system isn't on dead trees doesn't disqualify a music album from the running.
One thing the professor could do is take the student aside and ask them to defend their choice or set slightly different parameters for the assignment. If the student can articulate why the album is a good substitution or point out poetic devices in certain tracks, it would allow the professor to gauge the student's knowledge of poetics. Plus, it might help said student maintain interest in a long project. We often remember things we learn when the format is more enjoyable; more joy in this world is rarely a bad idea.