First she took life One Day At A Time, then after battling drug addiction, she became a musical Mama with her real-life papa. Now she'll be at Town Hall, Feb. 27, in a concert devoted to songs from Broadway musicals in the 1970s.

She's Mackenzie Phillips, and she'll be joined in Just For Tonight: A 70s Broadway Songbook by Sean McDermott (Miss Saigon), Tara O'Brien (Victor/Victoria) and Edward Staudenmayer (Forbidden Broadway Strikes Back). Phillips reached early stardom playing a teen on TV's "One Day At A Time" but ended up leaving that show due to various bouts with substance abuse. She resurfaced, 1982-92 when she joined her father's band, The Mamas and the Papas, on tour. She also appeared on Broadway in the musical revival, Grease!.

A cross between a cabaret show and a two-act musical, Just For Tonight willl feature tunes by Marvin Hamlisch, Steven Sondheim, Tim Rice and Andrew Lloyd Webber. Backed by a grand piano, it's the first in a new series at Town Hall titled, "Century of Change." The show is a one night benefit for Town Hall to coincide with a recent matching grant.

Phillips told Playbill On-Line (Feb. 24), "I'm not familiar with show music that much. I come from a rock and roll background. But I love theatre. I did Grease!, but that really isn't traditional musical theatre." In the benefit, Phillips will sing "To Make The Boy A Man," from Goodtime Charley; "Time Heals Everything," from Mack and Mabel; "Just For Tonight" from They're Playing Our Song; "I'm Still Here" from Follies and even Send in the Clowns from A Little Night Music.

Other shows represented include Minnie's Boys, Snoopy, and Sweeney Todd ("Pretty Women"). Said Phillips, "There's also a a great song called "Solid Silver Platform Shoes," from The Magic Show, which people probably don't even remember. But the whole show is a songbook, with very little banter." "The goal isn't really to get on Broadway," said Phillips. "I just want to be a working actor. I've been doing a lot of episodic television work ["NYPD Blue," "Beverly Hills 90210"], so here I just want to be productive and enjoy these other great singers."

For tickets ($15-$25) and information on Just For Tonight at Town Hall, 123 West 43rd St., call (212) 307-4100.

-- By David Lefkowitz