North and south, east and west, the many smaller theaters of Pittsburgh provide a substantial supplement to the offerings of the professionals. To some audiences, they may also be better-known, as with these two, the long-established Little Lake Theater (now in its 61st season) and Pittsburgh Savoyards (in its 71st ).

With this intriguing British play by Sarah Wooley, Little Lake boasts of a U.S. premiere -- which is not as unlikely as you might think, under the ambitious founding leadership of Will Disney and now for many years of his daughter, Sunny Disney Fitchett, and her husband, Rob. In a typical season of about a dozen plays, running from May to December, they almost invariably schedule premieres of several kinds -- regional, U.S. or even world.

Little Lake also goes well beyond the familiar suburban theater fare of mysteries, farces and family classics. Witness this current offering, a serious play with a touch of the whodunit about a puzzling young American who shows up in the lonesome home of an English couple and claims to be the son they lost on a vacation in the States 22 years before, when he was 5.

The husband isn't buying, it but his wife is overjoyed, and in a series of six mainly two-person scenes -- husband and wife, husband and young man, young man and wife, etc. -- we soon see that the question of the young man's true identity is complicated by that of the older couple's relationship. Why is the husband so adamant about what seems a mystery? Just what did happen those many years ago?

You'll have to go to Little Lake to find out, and the trip will be worth it even without indulging in the tempting desserts they serve at intermission, because this is a taut, skillful realization of an intriguing small drama. I have some quibbles about how it all plays out, not quite living up to its earlier scenes, with their terse, tantalizing enigma reminiscent of Pinter. But it holds us close.

And I can't quibble with Fitchett's direction or the acting of Warren Ashburn (father), Lynne Franks (mother) and Don DiGiulio (young man). Ashburn is especially fine, his certainty giving him an eerie advantage over the other two, who are more obviously needy. With a couple of twists up its sleeve, you probably won't anticipate just how it comes out.

Little Lake Theatre, 500 Lakeside Drive South, Canonsburg; through Nov. 7: Thurs.-Sat. 8 p.m. (but not Oct. 31); $15-$17; 724-745-6300.

And now for something completely different, as the Pythons would say. Indeed, there is something Pythonesque about the humor of wordsmith William Gilbert and his melody-spinning partner, Arthur Sullivan, but any influence must run the other way, since "Patience" was first staged in 1881, the sixth of the famous duo's 14 collaborations.

In fact, without G&S it's hard to imagine most 20th century British or American musical stage humor. "Patience" may not equal "Pirates of Penzance" or my own favorite, "Iolanthe," but it perfectly epitomizes the G&S mode of genial topsy-turvy humor, rising toward gently biting satire, always accompanied by Sullivan's lively and sometimes beautiful score.

The story finds a company of British soldiers unable to make amorous headway with the "20 lovesick maidens" of the vicinity, because the ladies lavish all their infatuation on Bunthorne, a poseur of a poet in the aesthetic style of the day. But he pursues only Patience, a milkmaid, who has the wit to find him repellent. Enter another poet, the vain Grosvenor, and the ladies' devotion is swayed. So is Patience, but idealist qualms come between them. Meanwhile, the soldiers can only bluster and fume as the competition between the two poets comes to a boil.

It used to be reckoned that Bunthorne and Grosvenor were caricatures of Algernon Swinburne and Oscar Wilde, but they also allude to others, the fads of aestheticism and the pastoral being Gilbert's target. Poets, soldiers and ladies are all ridiculous, all are given lyrical masterpieces to sing, usually in contrast to Gilbert's witty lyrics.

The Savoyards are unlike any other amateur theater around, more club than company, mixing amateurs and semi-pros, and they generally field a capable orchestra of about 20. I had a bad head cold when I saw "Patience," I'm less able than usual to comment on the musical achievement. Nonetheless, I can say musical director Guy Russo and his orchestra made a good show of Sullivan, while stage director Shane Valenzi did adequately by Gilbert.

I was especially impressed by young Hannah Taylor as Patience. There's usually some arch humor in the G&S ingénue being played by a mature woman who parodies the cliche. But Taylor, 17, is the real thing, all truthful naivete, not acting the part so much as inhabiting it with charm, and those with clearer sinuses than I agreed she sings like an angel.

Corey Nile Wingard and Jonah Winter play the very camp, affected poets and land most of the jokes, Wingard especially, and Leon Zionts is better than capable as the bewildered leader of her majesty's dragoons. A lot of the heavy lifting falls to the other comic roles, the duke played by Garth Schafer and the scorned woman, who is given much zest by Meighan Lloyd.

Regrettably, the ensembles aren't as big as you'd like -- eight village women have to do for the 20 lovesick maidens, with a chorus of dragoons to match. But they acquit themselves with energy to the extent of their abilities. Coming in the spring: "The Mikado."

Pittsburgh Savoyards Catherine Thomas Theatre, Benedictine Center, Ross (I-279, Perrysville exit); through Sun.: Fri.-Sat. 8 p.m., Sun. 2:30 p.m.; $15-$20; 412-734-8476 or www.pittsburghsavoyards.org.

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