Off Broadway Serves Up Plays and Musical Comedies Both Sweet and Sour

Camping With Henry & Tom

At the Lucille Lortel Theatre.

Mark St. Germain's history-based play imagines what might have happened during a 1921 camping trip taken by President Warren Harding, Henry Ford, and Thomas Edison. In it, these three estimable figures become stranded, and in the ensuing hours their true natures are revealed.

What's most surprising about the comedy-drama is that Harding winds up as the most interesting character. He is portrayed as a reluctant president whose greatest pleasure lies in hours of handshaking with common folk on the White House lawn. Any similarities to Ronald Reagan may or may not be intentional.

Harding is also depicted as a genuinely decent man, a man of real emotion, who can't bring himself to kill the deer that caused the car crash that got them stuck in the woods. He contrasts well with Edison, portrayed as a cynical, wisecracking curmudgeon whose deafness comes and goes at his convenience, or Ford, depicted as an ambitious, racist demagogue.

There is a certain thrill in seeing such fascinating historical figures come to life (the best example of this is ''1776''), but the playwright, despite his obvious enthusiasm for the characters, doesn't succeed in mining the situation for any deeper resonance. The banter is engaging and often quite funny, but it isn't long before we are as eager as they are to be rescued. Helping the evening greatly are the wonderful performances: Robert Prosky (Edison), Ken Howard (Harding), and John Cunningham (Ford) bring lively charm to their characterizations.

Silence, Cunning, Exile

At the Joseph Papp Public Theater.

Although Stuart Greeman's play is ''inspired by events in the life of Diane Arbus,'' you would hardly know it, save for the camera dangling from the neck of the lead character, Suzie (Elizabeth Marvel). The actress looks like Arbus and invests the part with the right intensity, but the play is so fragmented and elliptical that barely a coherent theme or idea squeaks through.

The evening reveals Suzie's transformation from fashion photographer to chronicler of the seamy underside of New York and its more bizarre inhabitants. It also explores the bizarre relationship between her and her husband (Denis O'Hare), and their best friends, Frank (Tim Hopper), who is in love with Suzie, and his wife, Beryl (Margaret Whitton). The societal changes that occurred from the conformist 1950s to the exploding '60s are also touched upon.

The play is directed within an inch of its life by Mark Wing-Davey, who is constantly utilizing flashy techniques to lend some weight to an otherwise thin evening. The play begins and ends with bright lights flashing and shutters clicking. Short, loud fragments of '60s rock songs are employed to transmit a sense of ironic atmosphere.

Some very capable performers are trapped in this, desperately trying to lend credence to their underdeveloped characters. The program notes proudly describe how the director put his actors through a mini-course on photography and the history of the period. The time would have been better spent developing the script.

Call Me Madam

At City Center.

Who would have thought that Tyne Daly would become a great musical-comedy actress? In the recent Encores concert version of ''Call Me Madam,'' she demonstrates that the star power she displayed several years ago in ''Gypsy'' was no fluke.

Daly stars in Irving Berlin's musical as Sally Adams, a high-society party-giver who winds up as ambassador to a European country (the musical was inspired by the career of Perle Mesta, whom President Truman made ambassador to Luxembourg). Daly dazzles with her comic energy and charisma. The show itself, although only a staged concert reading, was easily the best in this series so far, and one of the highlights of the musical-theater season.

The work is somewhat dated, but Berlin's tuneful score is a marvel: Half the audience left whistling ''It's a Lovely Day.''

Look for performances of Cole Porter's ''Out of This World'' (March 30 to April 1) and Rodgers and Hart's ''Pal Joey'' (May 4 to 6).

Rosemary Clooney

At the Rainbow & Stars.

''Demi-Centennial,'' the title of Rosemary Clooney's fine new album (Concord Jazz), refers to the singer's 50th year in show business. It's an occasion worth celebrating, as is her engagement at Rainbow & Stars, New York's elegant nightspot at the top of the General Electric building.

Clooney's voice has deepened and coarsened over time, but like all the truly great singers, she doesn't let that hamper her. If anything, her interpretations have become all the more forceful for their quiet, conversational style. The album, from which her act is largely drawn, is composed of songs that have a personal connection for the singer. These include a quiet and powerfully emotional ''Danny Boy''; her early hit ''The Coffee Song''; and Stephen Sondheim's ''Old Friends,'' which she introduces with an audio clip of a radio broadcast featuring her kidding around with Bing Crosby and Bob Hope.

All of these numbers are invested with a seasoned maturity and performed by a still-caressing voice that seems particularly warming on a winter's night. Displaying a sense of humor about herself, Clooney demonstrated a lack of pretension that belied the exalted stature of her career.

Her gig here has become an annual engagement: You won't be able to see her in such close quarters anywhere else.