Euphonious has a budget of about $250,000, Metrock says, and a sizable chunk of it is earmarked for the bands. “I wanted acts that I knew were rock solid, banging live acts,” he says.

Tickets for Euphonious are $500 per night for “socially distanced squares” that are 10 feet long by 10 feet wide on the zoo’s lawn. Each square has a limit of eight people.

Last night, Tedeschi Trucks Band performed at Prudential Hall at New Jersey Perform Arts Center in Newark, N.J. Over the course of the performance, the 12-piece blues-rock ensemble led by ...