“Musical” is put together by the Miami artist Dara Friedman, who works primarily with film. (She has a work currently at the Museum of Modern Art and recently had a show at the Kitchen in Chelsea.) Last year Rochelle Steiner, the director of the Public Art Fund, which commissions and presents exhibitions in public spaces in New York, encouraged Ms. Friedman to do something for the fund.  Ms. Friedman didn’t want to do the old projection-of-an-art-film-onto-a-screen-in-Times Square kind of thing. She was inspired by Walt Whitman’s poems about Manhattan, an idea about giving what might otherwise be private and personal performances a chance to be heard in public and a memory of watching a woman break into “Amazing Grace” amid the hubbub of Grand Central years ago.  “What I’m really interested in doing,” Ms. Friedman said, “is making sure the spectator pays attention, forcing you to be excited. Alter somebody’s rhythm, where, all of a sudden, you’re paying attention.”  So arose the idea of “Musical”: She would film people bursting into song all over Midtown and uptown over the course of three weeks, ending next Friday.  Ms. Friedman and people from the fund sent e-mails to friends and took out advertisements in The Village Voice, Backstage and Craigslist and on the listservs at Juilliard and the Tisch School of the Arts at New York University.  “Sing ‘your song’ a cappella, with feeling, like you mean it, on the streets of Midtown,” read the ads. “College students, office workers, mothers, schoolchildren, taxi drivers, doormen, tourists, divas and grandparents — come and sing for us, in your city. Payment: $120.”  Eighty or so people showed up for auditions early last month at Passerby, a bar in Chelsea (which Ms. Friedman’s husband, Mark Handforth, designed). The hopefuls sang, but Ms. Friedman doesn’t really know from singing; she was looking for people who were comfortable “singing in their own space in public,” performers who would not engage with the spectators but would create a little corona around themselves on a crowded sidewalk.  The singers, about 60 of them, have been performing solo and in groups at different times and places around Manhattan over the past two weeks while Ms. Friedman and her discreet crew stand a few feet away and shoot surreptitiously. She hasn’t yet decided what will be done with all of the sequences.  In any case, there has already been an audience, which is also the supporting cast. The idea of the project is not to record the reactions of people walking by (that would make it merely an episode of “Punk’d”) but to make them part of the project.  After all, Ms. Friedman said, just about all people have wanted at some point to sing out loud whatever they’re singing inside their heads. So both the woman in Central Park who was unaffiliated with the project yet burst into song on her own, and the indifferent bystanders with headphones and cellphones shoved in their ears are part of the show, engaging with public expression in different ways.  But nobody has a perspective like the singers themselves.  “At first, I think I’m going to stick out like a sore thumb,” said Ms. McLean, the woman singing in Grand Central. But as soon as she starts, something intriguing happens, which is to say, nothing much happens at all. This is New York, and it will take more than some gal singing standards in Grand Central to slow down that wheel of life that Strayhorn was talking about.  The policeman on the staircase barely looks up; the two little girls beside him continue giggling about whatever it was they had been giggling about.  “For a second,” Ms. McLean said afterward, “you’re like, ‘Am I doing this in my head or am I doing this?’”  She walks down the stairs and hits a crescendo: “‘Romance is mush/Stifling those who strive/ I’ll live a lush life in some small diiiiive. ...’”  Two businessmen glance at each other cynically and keep walking. An unkempt woman stops to offer compliments. Two tourists look around, see no reaction and walk on. And those are the ones who are paying attention.  For a few minutes it’s as if everyone in Grand Central is actually in a musical, where somebody singing about unrequited love makes more sense than somebody not singing about it.  Then Ms. McLean turns and walks down into the dining concourse until she can’t be heard. “And it’s just over,” she said. “As if nothing happened.”  A version of this article appears in print on , on Page B7 of the New York edition with the headline: Turning All of Manhattan Into a Broadway Stage. Order Reprints| Today's Paper|Subscribe
“Musical,” a video project by Dara Friedman, features various people singing show tunes in public parts of Manhattan while a crew discreetly shoots them.