Big-voiced Mary Testa, the actress who landed so strongly in 1998 in William Finn's A New Brain and the Public Theater's revival of On the Town, will officially open her new cabaret act, Haile, Mary!, with pianist-music director Evans Haile, Feb. 9.

Previews began Feb. 5 at the Garrick restaurant in New York City and show continue to Mar. 6.

Testa and Haile, with Andrew Gerle on a second piano, will perform songs by Harold Arlen, George Gershwin, Rodgers and Hart and Ernesto Lecuona as part of the Garrick Gaieties at the intimate Garrick, at the Mayfair Hotel (242 W. 49th St.).

Performances are 9:30 PM Tuesday-Thursdays ($25 cover with dinner required; seating 8 PM) and 10:30 PM Friday-Saturday ($30 cover plus $15 food/drink minimum).

Scott Perrin, producer of Secrets Every Smart Traveler Should Know, is the producer for shows at the Garrick. Testa played the tipsy, dipso Madame Dilly, often stealing scenes in the Public's On the Town at the Delacorte in Central Park and at the Gershwin Theatre. She was the homeless woman in Finn's A New Brain at Lincoln Center Theater's Mitzi Newhouse in summer 1998, and was Domina in Jerry Zaks' revival of A Funny Thing Happened on the Way to the Forum. She also appeared in Lynn Ahrens and Stephen Flaherty's Lucky Stiff at Playwrights Horizons.

Haile is a frequent conductor with international symphonies. He also musical-directed studio recordings of Babes in Arms and Cole Porter's Fifty Million Frenchmen.

Gerle has accompanied Kitty Carlisle Hart, John Raitt, James Naughton and Jo Sullivan Loesser. His original musical, Kepler, was a finalist for the Richard Rodgers Award.

For information about the Garrick shows, call (212) 489-8600.

-- By Kenneth Jones