Blues poetry comes straight from the blues -- an American musical form with its roots in African music and the music of American slaves. Actually most American popular music (R&B, rock, rap, etc) is heavily influenced by the blues. it is also basically the most essential, visceral music there is, I THINK. Definitely my favourite musical genre, especially the old stuff.
According to the Handbook, blues poems may or may not follow the structure of traditional blues music. As you might expect, however, they always reflect "blue" content -- loss, hardship, hopelessness. Blues aren't depressing, though -- they acknowledge and accept the reality of the human condition, and i think say something about the endurance of the human spirit. They aren't songs about giving up. Occasionally, too, the blues have something to say about the humour to be found in bad places.
Before you try to write blues poetry, get a feel for the structure and tradition of blues music. I like to create stations on Pandora based on old performers like Bessie Smith, Howlin' Wolf, Lead Belly and the like.
Here are a couple of classics to get you started:
yup, totes put Led Zeppelin on there.
so yeah, have some fun with that stuff if you like. In a couple days i'll post some examples of blues poetry by peoples who knew what they were doing. Then i'll share a few of my amateurish attempts (^_^)