Wit and music by a P.D.Q. Bach gone pop. And - a well-acted romantic comedy, sentimental and trendy

Oil City Symphony Musical entertainment by and with Mike Craver, Mark Hardwick, Debra Monk, and Mary Murfitt. Additional music from various sources. Directed by Larry Forde. ``Oil City Symphony,'' at the Circle in the Square (Downtown), interprets musical comedy in its literal, delightful, and logical meanings. That is to say, the music is mostly comedic and the comedy is musical. The resulting recital reunites writer-performers Mike Craver, Mark Hardwick, Debra Monk, and Mary Murfitt on the stage of the gymnasium at mythical Oil City High School, from which these musical whiz kids graduated in the 1960s.

The pleasurable potpourri might be termed a collection of moments musicale as if assembled by a P.D.Q. Bach gone pop. The affectionate spoofery pays tribute to all those high school stars who achieved their moment of glory and who, in this case, dedicate their concert to the teacher who inspired them.

As an introduction, the amusingly differentiated cast members deliver brief biographies and describe their instruments: Mark, the piano; Mary, the violin; Debra, the drums, which she likes to think of as ``the United Nations of instruments''; and Mike, the all-encompassing synthesizer.

Among them, the Oil City virtuosos have written such songs as ``Ohio Afternoon,'' the ultimate regional anthem; ``Beaver Ball at the Bug Club'' and ``Beehive Polka,'' naturals for sound effects; and ``My Old Kentucky Rock and Roll Home,'' which jolts Stephen Foster into the world of Jerry Lee Lewis.

The quartet also draws inspiration, compositions, or both from the works of Franz Liszt, John Philip Sousa, Frank Loesser, and others. Mark displays his wit and virtuosic pianism in solos ranging from longhair classics to the ivory-tickling intricacies of Zez Confrey. Besides her intense ``Czardas,'' the prim Mary solos on saxophone and flute. Percussionist Debra matches syncopation with determination. Mike demonstrates the range and imitative possibilities of the synthesizer. ``Oil City Symphony'' responds equally to ``Hokey Pokey'' capers and the serene quietude of the unaccompanied ``In the Sweet By and By'' - in both of which the audience happily participates.

Set designer Jeffrey Schissler has transformed the Circle in the Square into a gymnasium auditorium replete with banners, crepe paper streamers, potted plants, and a basketball hoop.

The deft direction is by Larry Forde, the cheerful lighting by Natasha Katz, and the sound design by Otts Munderloh.

Historical footnote: Mr. Hardwick and Ms. Monk co-wrote and appeared in ``Pump Boys and Dinettes,'' a 1981-82 Off Broadway and Broadway hit; Mr. Craver is a former member of the Red Clay Ramblers, recalled locally for their notable contribution to Sam Shepard's ``A Lie of the Mind.''

Frankie and Johnny in the Clair de Lune Play by Terrence McNally. Directed by Paul Benedict.

``Frankie and Johnny in the Clair de Lune'' is at heart a sentimentally old-fashioned romantic comedy. Terrence McNally might have deepened his slight play and heightened its appeal for many playgoers by cutting down on the explicit sex and illuminating more fully the irreconcilables that initially complicate the relationship between Frankie (Kathy Bates) and Johnny (Kenneth Welsh).

Johnny is head cook at the restaurant where Frankie works as a waitress. He talks a lot, quotes Shakespeare, and uses big words. She contains her disappointment as a once would-be actress, but rues her looks and age (late 30s) and cherishes a nostalgia for the music of the Beatles. To Frankie's initial annoyance, the two share an exceptional number of the coincidences which Shaw said life is full of and which Mr. McNally finds comically usable.

Beneath its trendy frankness and bedroom humor, the dramatic thrust of ``Frankie and Johnny...'' lies in the dismay with which the skeptical Frankie responds to Johnny's sudden but ardently sincere declarations of love. She would settle for the prospect of casual sex with no commitments. He proposes marriage and a family. Never mind the bruises each has suffered - Johnny from a failed marriage, Frankie from a sadistic lover. Leave the rest to McNally, Debussy, and the moonlight.

``Frankie and Johnny...'' relies comfortably on McNally's deft comic style and the sensitive perceptions of Miss Bates's and Mr. Welsh's beautifully matched performances, under the direction of Paul Benedict. James Noone designed the efficiency apartment setting for the Manhattan Theatre Club production, with lighting by David Noling and costumes (what there are of them) by David Woolard.

The play is scheduled to run through Nov. 29.