An aria in an opera - Handel's 'Ombra mai fu,' for example - gets along with an incredibly small number of words and ideas and a large amount of variation and repetition. That's the beauty of it. It's not taxing to the listener's intelligence because if you haven't heard it the first time round, it'll come around again.

Considering the wealth of poetic drama that has come down to us from the Elizabethan and Jacobean periods, it is surprising that so little of any value has been added since.

Generally speaking, rhyme is the marker for the end of a line. The first rhyme-word is like a challenge thrown down, which the poem itself has to respond to.

If you're writing a song, you have to write something that can be understood serially. When you're reading a poem that's written for the page, your eye can skip up and down. You can see the thing whole. But you're not going to see the thing whole in the song. You're going to hear it in series, and you can't skip back.