The movie stars who showed up for the March 21 opening-night curtain call of “Hands on a Hardbody” weren’t the usual Hollywood types. They were the real-life subjects of the 1997 doc on which the Broadway tuner is based.

Book writer Doug Wright introduced them and brought them out on the Brooks Atkinson stage to bask in aud applause. Thesp Hunter Foster, it turns out, is almost the spitting image of Benny Perkins, the character he plays in the show about an endurance contest to win a new truck. Cindy Barnes, the organizer of the contest in the doc, shyly kept trying to hide behind Connie Ray, the actress who portrays her, while J.D. Drew — the ultimate winner of the contest in the movie, played onstage by Keith Carradine — showed up in a classy tux.

Was it wrong to be surprised that Trey Anastasio, the tuner’s composer and the frontman of jam-rock band Phish, also showed up in a suit?  “Actually, I wear a lot of suits,” he said at the afterparty at the Roseland Ballroom, defying the stereotype that all rockers wear hole-riddled jeans and frayed T-shirts. “I dress down to play in Phish.”

The country sound of the tuner isn’t what Anastasio usually writes for Phish, so he went to Nashville to do some research. “The best piece of advice I got was from a fiddle player who told me that the first country hit, back in the 1920s, was the same year the U.S. census said more people were living in cities than were living in the country. So every country song is about wanting to go home. It’s not a sound. It’s a feeling.”