The British Embassy Players are in a fair way to give amateur theatrics a bad name. They are so good, and so inventive, and so tireless, as to put most other nonprofessional theater groups in the shade.

"Music Hall 1981" is the 17th annual blow-off at the British Embassy Rotunda, and the 64th production put on by players who for the most part spend their days On Her Majesty's Service. As always, it's being done for charity and for fun; as ever, the show if fully up to the standards British diplomats have maintained in such far-flung posts as Kampala, the Khyber Pass and Federal City.

Part of the show's charm is its wit and warmth; the rest is that it's so Britishly unlike the British as we normally see them in Our Town: broad, bawdy, rollicking. One is the more titillated for knowing that the beautiful, leggy, lascivious girls in the kick line are respectable ladies in real life, and that the leering rakehells who pursue them onstage occupy positions of trust and honor.

Master of Ceremonies Malcolm Edwards is so infectious he even had Sen. Harry Flood Byrd Jr., that silver-haired and severely Independent Virginian, waving his beer mug and singing along on opening night.

That's the good news. The bad news is that, if you haven't already been invited to buy a ticket, you can't get one for love nor money. The show is sold out by invitation.But, after the run at the Embassy ends on June 7, the show may be engaged for one-night stands anywhere in the region, either as a straight benefit or for a negotiated fee to be donated to charity. Inquiries are accepted by mail only by the Secretary, British Embassy Players, 3100 Massachusetts Avenue NW, Washington DC 20008.