There really isn't one, what you need to look at are the words that are used to make it seem dirge. It's a person own style for things such as rhyme and structure.
For example of choice of words look at Seamus Heaney's poem of first stanza
I sat all morning in the college sick bay
Counting bells knelling classes to a close.
At two o'clock our neighbors drove me home.
sick bay is an unpleasant place
knelling bells are for funerals
parents didn't pick you up so something must have happened
The rhyme scheme.
A riddle is a question with a clever or funny answer, often based on a pun. It may or may not rhyme.
The poem "The Sea" does not have a consistent rhyme scheme as it is a free verse poem, meaning it does not follow a particular pattern of rhyme or meter.
You can measure or indicate the rhyme scheme of a poem using the lines of the poems which are represented by numbers such as AABB or ABABA.
Free Verse Poems
Rhyme Scheme
the rhyme scheme is AABBCCDDEEFFGGHHIIJJKKLL
The rhyme scheme is ababcc.
There is no specific rhyme scheme for a calligram
A rhyme scheme can be anything you like.
The rhyme scheme of "Mother to Son" by Langston Hughes is irregular and does not follow a specific pattern throughout the poem.
The name for the rhyme scheme AABB is known as a "couplet rhyme scheme." This means that every two lines rhyme with each other.