A "folly" in the architectural sense of the term is an elaborate structure, unusual and unique in design, quite expensive, and often built out of whim rather than purpose. As they pass the ninety-seven minutes of the play in the structure that gives the work its title, Matt elicits from Sally a bit of family history: that the builder was called "Whistler" because he whistled and sang a lot. (His signature piece was "Una furtiva lagrima" from Donizetti's L'elisir d'amore, but since none of the locals knew much about Italian opera, they merely thought him daft.) Uncle Whistler had built the boathouse and, in addition, the bandstand from which music drifts across the river on this Fourth of July evening.

The title of the play also refers to Sally's choice of a husband. Matt, a good ten years older than she and rather alien with his faint...