Give "It's Alright Ma' I'm Only Bleeding" a listen - I think that's about as close to rap as Bob ever achieved...
Is Bob Dylan’s “visions of Joanne” a rap song?
Aside from the content not being about the usual Rap music topics; the form, rhyming, rhythm, and singing are fundamentally the same. Listen to it again fresh with that thought in the back of your mind. Discuss this politely with me if you like, this an open question, not a statement of fact. I’d like to hear different opinions.