‘Hair’-raising benefit

Alexander emcees songfest

Thesps threw off their inhibitions for a flower-power packed 11th annual A Night at Sardi’s Benefiting the Alzheimer’s Assn. at the BevHilton Wednesday night.

Jason Alexander served as a shaggy emcee to a cast of groovy belters, including Eric McCormack and Megan Mullally of “Will & Grace,” Victor Garber, Jean Smart, Sharon Lawrence, Karla DeVito, Hattie Winston and Bruce Vilanch. Sam Harris, who recently starred as Claude in a revival of “Hair” at the Wadsworth Theater, said he was relieved to finally sing his solo from the 1960s musical fully clothed.

The cast of “Frasier” (sans Kelsey Grammer) sang the title song clad in nude suits with strategically placed daisies and peace signs for the benefit’s finale.

“Every year we try to do something that will really upset people,” David Hyde Pierce said through a beard that reached his knees. “This year, I think we succeeded.”

Original “Hair” producer Michael Butler was joined in the packed audience by longtime Alzheimer’s Assn. supporters Soliel Moon Fryeand William H. Macy, who received the org’s Entertainment award for co-writing telepic “Door to Door.”

Honorary chair Shelly Fabares said she has no plans to don the peace beads and sing next year, preferring to leave the performances to the Broadway-style belters.