A rondelet is a short fixed poem of seven lines. Its first line comes back as the third and seventh lines, creating a strong refrain, and the poem usually works with only two end rhymes. Because of its tight repetition, the rondelet often feels circular, musical, and carefully compressed.
Example
Morning light on the harbor wall
Lifts the gulls before they call
Morning light on the harbor wall
Silver on the oars and sail
Wind moves softly through the squall
Tide keeps time with every fall
Morning light on the harbor wall