"Ballad of the Landlord" is a super fun poem to read. It's not a happy poem, but there are humorous moments in it. The reason that I think it is a fun poem to read is because it is written in simple language, it tells a story, rhymes, and is immediately accessible. The rhyming story being told in short poetic stanzas is what a ballad is. There is some variation in the format, but in general ballads contain four line stanzas that are written in ABAB rhyme scheme. Hughes follows the four line stanza rule for most of the poem. Stanzas 1-6 follow the rule. The final stanzas do not. Hughes also generally sticks to an ABCB rhyme scheme; however, stanza 3 does the same rhyme for all four lines. That would be AAAA rhyme scheme.
The poem is also not narrated by the same speaker throughout the entire poem, which is a change from a standard ballad. The first five stanzas are all spoken by the tenant. The sixth stanza is spoken by the landlord, and the final stanzas of the poem shift to a hypothetical society and newspaper headline.
Lastly, ballads tend to typically be happy poems about love and romance, but this poem focuses on a social injustice. The first injustice is how the landlord is taking advantage of his tenant, and the second injustice is the tenant's punishment which seems to be a result of his race.