Well-Tempered Mix of the Mystical And Whimsical. THEATER REVIEW.

Cantorial. Play by Ira Levin. Directed by Charles Maryan. AS he proved in such works as ``Rosemary's Baby'' and ``Veronica's Room,'' Ira Levin is no stranger to the bizarre with supernatural trimmings. In ``Cantorial,'' his genial new comedy at the Lamb's Theatre, Mr. Levin mingles supernatural and religious themes, the mystical and whimsical. The elements are nicely blended in the well-tempered production staged by Charles Maryan.

``Cantorial'' opens as Warren Ives (Anthony Fusco) and girlfriend Lesley Rosen (Lesly Kahn) are taking possession of their home, a remodeled synagogue on Manhattan's Lower East Side. But it becomes immediately evident that they aren't the sole possessors. Being practical moderns - Warren is a Wall Street futures trader and Lesley a publisher's publicist - they naturally assume that the eerie vocalizing to which they are subjected must be a practical joke. They soon discover otherwise.

With the help of friendly neighborhood Jewish grocer Morris Lipkind (a mellow Woody Romoff), they learn that the disembodied voice belongs to a cantor who died in 1943 and now demands that the premises be restored to its original purpose.Over Lesley's objections and with Morris as his skeptical guide, Warren begins tearing down walls and exposing the former synagogue's altar.

An adopted child, Warren even convinces himself that his natural mother must have been Jewish. Unable to persuade him to seek psychiatric help, Lesley packs up and leaves.

As the mover of these events, Mr. Levin remains on the side of the angels, or at least of Warren's emerging convictions. With the help of scene designer Atkin Pace, the synagogue is gradually reclaimed. By the time Warren's baffled father (Robert Nichols) arrives with belated parental explanations, Warren has repaired the altar, complete with rail, and is installing the elaborate ``eternal light'' candlesticks. To suit the prevailing mood, Mr. Levin brings ``Cantorial'' to a happy resolution.

In its own sweet way, the comedy rationalizes the yearning that motivates Warren's obsession and gives credibility to the young worldling's newfound commitment, an attitude eloquently realized in Mr. Fusco's dedicated performance. Mr. Romoff's Morris personifies urban Jewish patriarchalism - kind, shrewd, humorous, and philosophical.

As the conflictive element in the equation, the attractive Miss Kahn depicts a secular contemporary whose own Jewish roots do not initially prompt her to share in Warren's restoration project. Paul Zim is in splendid voice as the disembodied cantor; James DeMarse and Joan Howe do nicely as a drop-in couple.

``Cantorial,'' which was lighted by Brian Nason and costumed by Lana Fritz, was originally produced in New York by the Jewish Repertory Theatre.