Speaking of villanelles, I went on a Google quest to get a clearer idea of what their evolution was, and found a 19th-century (post-Romantic or "Parnassian") poem by Théophile Gautier that has exactly zero in common with the villanelle (three eight-line stanzas, no refrains) but I happened to recognize it as the text of one of the best songs ever written, which I know as music instead of poetry, the first number of Berlioz's Nuits d'Été. I had no idea it was entitled "Villanelle" but it is and I had to post it because I love it so much, plus it's pretty short and seasonally appropriate (weather in New York is chilly and rainy and so awful I'm cooking chicken soup for the old lady, but we know spring is here). The soprano is the pretty famous Véronique Gens, and she sings the whole wonderful cycle (about half an hour) here.
"When the new season arrives, and the cold has vanished, the two of us will go, my beauty, to pick the lilies of the valley in the woods, breaking the morning pearls of dew like grapes under our feet, and hearing the blackbirds—
Spring is here, my beauty, the month that lovers bless, and the bird, smoothing its wing to silk, recites poetry on the edge of the nest. Oh come sit with me on this mossy bank and talk about our lovely love and tell me with your sweet voice—
Going far, so far, letting our path wander, we'll frighten the hidden rabbit, and the stag, bending to admire his big antlers in the mirror of the spring, until, happy and at ease, fingers entwined, we get back with a basket of strawberries—
From the woods!"
(my translation, French text here)