I was introduced to a new poetic form the other day. It's called the Pantoum, and it's one of the most brilliant forms I've encountered. It originates from Malaysian, often used in song form, and it goes something like this:

First line
Second Line
Third Line
Fourth Line

Last Second Line
New Second Line
Last Fourth Line
New Fourth Line

.
.
.
.

Last Second Line
Original Second Line
Last Fourth Line
Original First Line

The structured repetitions produce a hypnotic trance state. I will try to find examples of them.