Public Theater’s colorful revival of “Hair,” all dressed up for an extended road tour, promises to evoke vivid flashbacks for veterans of the psychedelic 1960s while providing a zesty tutorial for younger generations wondering what the hubbub was all about. An exuberant young tribe of pros has descended on the Kennedy Center Opera House for a month of refreshing innocence — a rarity in the cynical nation’s capital — for what is one of the lengthiest bookings of the tuner’s 20-stop acid trip announced so far.

Hair

A musical recognized initially for its shock appeal has clearly been tamed by 40 years, even with its flash of nudity at the end of act one. But it’s no less satisfying thanks to an infectious collection of numbers preaching love, tolerance and flower power. Indeed, composer Galt MacDermot’s eclectic music still impresses, as do Gerome Ragni and James Rado’s eternal lyrics about intolerance, drugs, sex and rebellion. It is virtually impossible to walk out of this musical without a tune on your lips.

Supported by a 10-piece band and the sturdy direction of Diane Paulus, who keeps the crew faithful to the period, “Hair’s” touring cast members display boundless energy as they race through the aisles and cavort with the audience. Major roles are all in good hands, led by Steel Burkhardt’s athletic and precocious tribe leader Berger, who sets an early tone of naughtiness and high spirits. Ditto Phyre Hawkins’ full-throated treatment to opening number “Aquarius.”

Kaitlin Kiyan is the picture of innocence and vulnerability, especially in the enchanting number “Frank Mills.” So, too, is Kacie Sheik’s pregnant Jeannie, showing off her strong soprano in “Air.”

The whole affair is nicely attired in Scott Pask’s colorful set, the picture of psychedelic awareness.