Here's my comment on a post by Deborah Ager:
One can also write anagram poems in which each line is an anagram of the first. Once, when I was very agitated and depressed (breakup blues), I did it with Dylan titles:
You’re gonna make me lonesome when you go
where eyes go. Unmake me, you, long moon on a
lake. O one, go, how you unsang me, my mere one.
Go anger, you lone omen, when you make me so
alone, our unknown game, o my eye goes home.
I was amazed by how expressive such a constraint could be.