After he recovered from COVID-19 this spring, Brian Stokes Mitchell sang "The Impossible Dream" out the window of his New York home every night at 7 o'clock. But it wasn't a performance, he says. Instead, it was "a song of gratitude for the essential workers." That's why he didn't sing any other songs. To him, "The Impossible Dream" most accurately captured the experiences of the doctors, nurses and other first responders who were hard at work during the pandemic. Mitchell is a Tony Award-winning Broadway star who has also appeared in a number of live-action and animated television shows, including "Trapper John, M.D.," "The Fresh Prince of Bel-Air," "Frasier" and "Mr. Robot." He says he feels like "the luckiest actor in the world" because he's gotten to explore so many different kinds of roles. Live concerts are his favorite type of performance these days, Mitchell says, because he gets to design a show for the geographic area, the time and the context. Mitchell arranged, orchestrated