Conversation so far:
what type of poem is let america be america again
Let America be America Again is a sweet verse type poem so it has no regular meter.
What is Matsuo Bashō's Old Pond classified as?
The best-known Japanese haiku is Bashō's old pond:
What is the genre of Beowulf?
Beowulf is an Old English epic poem.
What is When I Consider How My Light is Spent regarded as?
When I Consider How My Light is Spent is one of the best known of the sonnets of John Milton.

Question: which category would Don't Go Gentle be classified?
Self-contained rewrite: Is the Dylan Thomas' Do not go gentle into that good night a type of poem?