[bitofhope]

I disagree. Song lyrics absolutely count as literature to me, as does the other poetry he was recognized for. He's not the first one to receive the Nobel for poetry either, and his themes and influence line up well with the stated goals of the prize itself.

[bloak]

Irrelevant sidetrack: The word "literature" is also applied to music without lyrics. Try googling for "keyboard literature" or "violin literature", for example. In English, at least. Don't know about Swedish!