Yet another reason Wikipedia is awesome:

In the entry for assonance (“the repetition of vowel sounds to create internal rhyming within phrases or sentences”), examples are given from a list of poets including Edgar Allen Poe, Alfred Lord Tennyson, Samuel Taylor Coleridge, Robert Louis Stevenson and… Big Pun!?!

Obviously, Pun’s contribution here was the immortal “Dead in the middle of little Italy, little did we know that we riddled two middle men who didn’t do diddily.”

Like Rakim said, “RAP is Rhythm And Poetry.”