WHOEVER SAID there were only two types of play, funny and sad, forgot the ones that pick'n'mix. In The Memory of Water, a very welcome theatre debut by Shelagh Stephenson (an ex-actress who has written several plays for radio), three bickering sisters gather at their childhood home in the north-east of England for their mother's funeral. In the mother's old bedroom, in this isolated cliff-top bungalow, the two types of play also slug it out. If they had got on together a little better, Stephenson would have a hit.

The funny one, which feels like a hilarious pilot for a sitcom, features Jane Booker (very adept at mundane comedy) as Teresa. She wears a sensible beige cardigan, mumsily folds her arms, purses her lips and gets on with the practical business of throwing her dead mother's clothes into bin- liners. Booker says everything you need to know about her own marriage in four words. As her husband, Frank, Dermot Crowley gives a masterly impersonation of a punctured tyre. Booker briskly tells him: "Frank. Bags. Car. Now."

Matilda Ziegler sweeps in as the youngest sister, the promiscuous, impoverished Catherine, as if from a broader comedy, laden with shopping. "Broke doesn't mean you can't buy things." She complains she's ovulating. No one pays her any attention. Ziegler excels at pert young women who look as if they have been wound up like alarm clocks. Mike Leigh should give her a part. You only wish her role here wasn't as insubstantial as the outfit she wears to the funeral.

The sad play, which keeps interrupting the funny one with its themes of guilt, loss and regret, centres on Haydn Gwynne as Mary, the sister who's a doctor. The three sisters work well together when there is a bitchy, girls'-dorm atmosphere and Gwynne is dishing out disdain and sarcasm. She's a natural Restoration actress: she has a long face and a long nose, and she loves to look down it. In other scenes, the sisters seem unrelated. One reason why Gwynne seems to have walked in from a different play is that she is the only character written convincingly from her own point of view. We laugh at the others' problems. We would never laugh at her troubled affair with a TV doctor, Mike (an engagingly relaxed performance from Alexander Hanson). He's the sympathetic New Man, who turns out to want the simple things in life: a wife, a mistress and no more kids. We would never laugh at Gwynne's fraught exchanges with the ghost of her mother (a hard-edged, bewildered Mary Jo Randle), who eerily appears in a green taffeta dress to remonstrate with her neglectful daughter. Gwynne leads us into a bleak emotional area, full of fury, disappointment and heartbreak. It's genuinely moving. That's the flaw. In Terry Johnson's production, as we shuttle between the extremes of Ziegler's comic vanities and Gwynne's grief, we find it an increasingly bumpy ride.

The new stage adaptation of Birdy, the William Wharton novel (1978) that became an Alan Parker film (1984), not only brings the revolve into a studio space, but employs two of them, one inside the other. Kevin Knight, the director and designer, fills the stage with a perforated steel dish, which looks as if it's been fished out of the base of a washing machine. As Birdy opens, Knight adds bludgeoning industrial sound-effects, flashing lights and clouds of stage smoke. All of which suggest very little that's specific to inner-city Philadelphia. A story about a man who thinks he is a bird might require more delicate imaginative flight.

The American playwright Naomi Wallace, whose Slaughter City premiered at the RSC in January, sensibly adapts Wharton by splitting the two central characters into their boyhood selves and older selves. So Young Al can urge Sergeant Al to give the prying psychiatrist a Sicilian smile (cool and slow) and the older Al will do so. In Time Out last week, Wharton said the central characters are two sides of the same person. So we have four people playing one person. If this makes the play choppy, Wallace compensates with some highly distinctive scenes. Corey Johnson plays Sergeant Al with a tough sincerity, his bandaged face concealing deeper wounds. When he finds his boyhood friend Birdy (Matthew Wait) squatting in a cell, flapping his arms and cocking his head, he tries to shovel food into his friend's mouth with a spoon. It doesn't work. So Johnson feeds him the way birds feed each other, mouth to mouth. Later, in an erotically charged scene, Young Al (Adam Garcia) demonstrates step- by- step to young Birdy (Tam Williams) what will happen and what he must do on his first date. Both scenes achieve a startling intimacy. These moments, acted with utter conviction by this strong cast, compel our attention far more than any state-of-the-art stage mechanisms.

The props had a bad attack of nerves at Promises, Promises, the first in a season of three American musicals at the Bridewell Theatre, a converted swimming pool off Fleet St. The handle came off the door. The cord came out of the telephone. A glass held out for the champagne was half-full of coffee. Oops. And the show slid off the rails.

This classic musical, with its unsentimental view of sexual relations in Manhattan, paved the way for Company. Promises, Promises offers us such an overwhelmingly narrow male perspective on adultery that it's actually quite revealing. It's based on Billy Wilder and IAL Diamond's screenplay for The Apartment, about a young clerk who rises in his insurance firm by letting his apartment out to executives who need somewhere to take a girl. It also has lovely gags from Neil Simon (who wrote the book) and jauntily endearing Sixties songs from Burt Bacharach and Hal David.

Unfortunately John JD Sheehan's under-cast, under-rehearsed production only hints at the show's charm. The cheap settings and uncertain lighting dampen any insouciance mustered by the chirpy young hero Chuck (Marcus Allen Cooper). Many of Neil Simon's feedlines are pushed too hard for the punchlines to surprise us. There are spirited cameos from Harry Dickman as the doctor next door, who is amazed at the number of women Chuck gets through, and Joyce Springer as the middle-aged drunken woman that Chuck picks up on Christmas Eve. In this disappointing revival it's best to follow Chuck's example and grab what pleasures you can.

Theatre details: Going Out, page 14.