OLD-TIME MUSIC HALL - At the embassy through June16. Call John B. Nicol, 462-1340.

The British Embassy Players have turned Her Majesty's Washington digs into an old-time music hall, to the delight of every Colonial who can manage to get hold of a ticket.

The Players' only claim to amateurism is that they don't get paid; they would put the cast of a typical Broadway musical to shame. In "Music Hall" they take dead aim at a modest target and hit it bang-on. Their consistently superb performances, combined with the neighborly cheerfulness of all the volunteers who handle the production details, make the show a giddy triumph.

Former embassy staffer John D. Palmer has returned from England to be master of ceremonies for this 15th annual production, and it is his precisely broad-enough playing of the role that keeps the show rocketing along. Audience participation is not only invited, it is bloody well demanded, fueled by pitchers of beer that appear on the crowded tables at an intemperate rate.

"The conceit of our setting is that the audience are habitues of London's Palace Theatre," Palmer says in his warmup, holding the punch line as long as only a Brit would dare, "or sons of habitues."

Corny jokes, fine choreography, zippy wit, treacly sentiment and beautiful vocals flit past the footlights almost faster than ear and eye can follow. There are half a dozen show-stopping duets and solos, but Palmer and the cast refuse to stop. They throw away lines that disciplined professionals would be tempted to milk, spending their material as casually as sheikhs scatter petro-dollars.

Producer-director Mahri Miller has been true to two centuries of English music-hall tradition in staging the show, except that if the commercial halls had been this good they never would have died.

Some of the shafts the show lets fly may pass over the head of anyone who is not an Anglophile with a background in Kipling and Bea Lillie, but it's not necessary to know what "to take the shilling" means to have a side-splitting time of it.

If the show has a star it has to be Len Prossor, who has made more than 300 appearances with the Players, but to name a few would be to slight the many. There is not a weak performance in the lot, nor a flaw to be found from the lighting to the costumes. The beer is even cold.