As you probably know, Bob Dylan, a musician, was awarded the Nobel prize. He was the first musician to receive the Nobel prize.
The Nobel committee, notably, seemed to avoid the word music when explaining why the prize was awarded. The press release simply states that the prize was awarded to Dylan "for having created new poetic expressions within the great American song tradition", i.e. that the committee is awarding the prize based on Dylan's ability as a poet. Sara Danius, Permanent Secretary of the Swedish Academy, described Dylan as a "great poet in the English tradition"; a poet, not a songwriter. And Danius also said that Dylan "should be read"; that's an odd statement to say about a musician, whose works are intended to be listened to.
All of this made me wonder: how does the Nobel committee define literature? I suspect that they describe Dylan as a poet because they consider poetry literature. But I then decided to look for a explanation for where exactly they draw the line, but I wasn't able to find one.
How does the Nobel committee define literature?