THE British Council is once again giving its support to the Hongkong Arts Festival by sponsoring three innovative programmes this year. The programmes are Der Rosenkavalier , a musical comedy by Richard Strauss, Royal Shakespeare Company's The Comedy of Errors and Deadly Serious , performed by Adventures in Motion Pictures. ''We have been sponsoring the Hongkong Arts Festival since 1972, but it has been on an on-and-off basis until 1988 when we started sponsoring the event every year,'' Ms Joies Ng, Assistant Arts Officer of the British Council, said. ''Since then, we have established a good working relationship with Hongkong Arts Festival Society Ltd and we try to sponsor three programmes a year.'' Der Rosenkavalier is a romantic opera featuring an enormous orchestra. Its luscious waltz-filled score evokes the glittering world of 18th-century Vienna, the setting for a bitter-sweet comedy exploring the pursuit of love and the passing of youth. It is the festival's most ambitious opera project to date, and it promises an unforgettable mix of thrilling music, opulence and memorable performances. The Hongkong Arts Festival Chorus and faculty members and students of the Hongkong Academy for Performing Arts are also involved in the opera. The Comedy of Errors features identical twins who are constantly mistaken for each other. With the intricate and hilarious adventure, the Royal Shakespeare Company creates a riotous panoply of spectacle and illusion. According to Mr Tseng Sun-man, General Manager of Hongkong Arts Festival Society Ltd, the response to the three programmes has been encouraging. ''Tickets for The Comedy of Errors were all sold out.'' ''One of the best-known theatre companies in the world, Royal Shakespeare Company builds on a long and distinguished history of theatre in Stratford-upon-Avon. Maybe because of this, the programmes has proved to be one of the most popular ones in this year's festival,'' Mr Tseng added. The third programme, Deadly Serious is divided into two parts. The first part is in black-and/-white and the second part, in colour. ''The dance, a kind of black comedy, involves a lot of irony. The first half of the dance is in black and white, and the second half features bright, lively colours,'' Mr Matthew Bourne, a member of the cast, said.