"First line" means something different in verse than in prose

[larryhammer]

First lines of works in progress, by way of goosing myself:

Melissa Patterson wanted to kiss the girls, dammit.
(novel I'm supposedly entering revisions for)

The birth went badly. First the mother died,
(poem I'm actually revising)

I leave as night shades: sky no longer black
(still trying to get my January sonnet to work) (ETA: done, though some lines need polish)

Elena of Morrin topped the ridge and looked down the valley at the keep -- her keep.
(novel I'm returning to drafting once I finish #1)

The war was going badly. From the start,
(poem I'm returning to drafting once I finish #2)

Plus a Sekrit Project, and a couple YAs and picture books still untouched from the last time I went "baaa!"

Though what I want to know is whether a Greek myth sex farce short story in formal verse is interstitial or cross-genre. And does the answer change if you toss in a giant pig? How do you tell the difference between interstitial and cross-genre, anyway?

---L.