The Triple Fool
two fools
First fool: falling in love. Second fool: writing whining poetry about it. He's mocking his own lovesick verse.
earth's crooked lanes
Literal Renaissance science—people thought underground channels filtered seawater into fresh water. Poetry as filtration system for grief.
fetters it in verse
**Fetters** = chains. Writing poetry chains up grief, makes it manageable. The metaphor is imprisonment, not expression.
set and sing
**Set** = compose music for. His poems are being turned into songs by musicians showing off their skills.
frees again
The musician un-chains the grief by performing it publicly. What poetry locked up, performance releases.
three fools
Third fool: letting his private pain become public entertainment. The 'triple' in the title.