In the Church Street theater downtown, a different kind of spring is blooming: the psychedelic flower-power of the Keegan Theatre production of the musical “Hair.”

“Spring is about new life, and I think that’s what this show is about,” says actor Paul Scanlan, who plays Claude, a leader of the band of hippies, or “tribe.”

The Keegan Theatre lets loose with its production of "Hair," featuring Paul Scanlan, above, as Claude. (Colin Smith)

“It’s these people who have new ideas and the absolute desire to spread them across the world and free their minds and their bodies from all these conventions that have been upheld for a really long time.”

Free indeed. A recent rehearsal began with a lecture on spreading germs through the many hand-rolled fake joints that are shared during the show. And the entire cast will appear fully nude onstage, a source of trepidation, and excitement, for the tribe.

“We all agreed to do the show knowing that there would be the possibility of getting naked,” Scanlan says. “But to do it in this sort of setting, the theater is so intimate. The front row is two feet from the stage.”

The promise of a nude scene has contributed to a closeness among the cast, Scanlan says. During rehearsal, they’ve become a bit of a tribe themselves, bringing in home-baked cookies and braiding each other’s hair.

And warm weather can’t come soon enough for actors who have to strip down past their skivvies. The old Church Street building, for which a massive renovation is planned, is drafty and uncomfortable, and the actors are at the mercy of the weather.

“At this time of year,” Scanlan says, “it is very cold. ... Now that we’re coming into the run, it will start getting warmer. ... It will be fine.”

“Hair,” Saturday through April 20 at the Keegan Theatre, 1742 Church St. NW. 703-892-0202. $37-$42. Because of language and nudity, children younger than 14 will not be admitted.