WHEN is a cymbal not a cymbal? When you can play it on a keyboard - and create the same effect. Some purists might suggest the synthetic version is not 'real music'. But according to the organisers of a new music festival starting tomorrow, they would do well to attend some of the concerts organised over the next few weeks. It might change their minds. 'Some people think that electronic music concerts are just recordings,' said Clarence Mak, electronic music lecturer at the Academy for Performing arts. 'What's the point of going to a live performance if it's just generated by a computer? Maybe 30 years ago that was true. But not now,' said Mak, composer of one of the pieces being performed at a concert of Multi-Media and Electro Acoustic Music at City Hall on Sunday. The concert work will indeed be pre-programmed. But part of the complex skills involved in electro-composition are programming random elements into the computer. 'You include random programming, but you have to control the degree of randomness. For example, we may decide that nine out of 10 times a chord will resolve itself, as a listener would expect. But that tenth time it will do something different, and surprise us.' The computer can also be programmed to create its own variations on a theme that the composer or musician introduces. 'As the composer we can hear the piece and say 'that was a good performance' or 'that was not the best I've heard', ' Mak said. 'If the performance was the same each time then it wouldn't really be meaningful.' In Mak's latest multi-media composition, sound is connected to lights and shapes: as a clarinetist plays, the colour on a screen changes with the tone colour, the shapes move and metamorphose according to the music's dynamics and rhythm. Mak started with the classical guitar, but he soon found an interest in what he could do with an electrified instrument, and from there moved into the field of musical synthesisers and how they could transform all musical instruments. He studied first at Pennsylvania State University, and later went to Stanford to study music programming on computer. When he returned from the United States, he was surprised to find that, with the exception of an old synthesiser at Chinese University ('very old, but good for learning on') there were no facilities for Hong Kong students to explore the seemingly limitless potential of electronic music. His proposal to set up electronic music courses at the APA was accepted, and Citibank put forward a lump sum to build and equip a studio. There he teaches programming ('It's important to know how to programme yourself - you can create electronic music without that knowledge, but then you are limited by the software writer's creativity') and composition. It is not, he emphasised, a specialist area for just a few students interested in a minor branch of musicology or sound research. 'Everyone can benefit from learning about how technology can help them - even the most traditional musicians. 'Hong Kong students are quite smart, but they are not very creative. Playing around with computers can help them expand their creativity. Also, knowing about acoustics helps students learn more about their instruments.' For example, he said, when you press down softly on the A key on a piano, so it does not make a sound, and then play an E, there is a vibration over the note. 'Musicians know that happens, but they don't know why. 'We also discuss why, when flautists and oboeists can play an octave higher when they overblow, clarinets have a different natural wavelength, and overblowing makes it an octave plus a perfect fifth higher. 'You need to consider such things when you're composing.' One of his research students is building up a 'library' of sounds made by Chinese instruments. It is easy enough to find electronic versions of violin, oboe and other Western instruments. Even Japanese instruments are available on disc. 'But no one has ever made a library of Chinese instruments,' he said, demonstrating a program where Chinese cymbals could be played on electronic keyboard. To the untrained ear, at least, they sounded convincing. 'It could be used to help people compose music for Chinese instruments: or it could be used in its own right in concerts, or for film music. 'We would like to put it on the market, but we're musicians. We don't know how to do all that stuff,' he admitted. The festival begins tomorrow with a performance of new work played by Trio Contrasts, a chamber group from Bucharest, who play flute, clarinet, saxophone, percussion and piano. On Sunday the Electro-Acoustic concert will feature work by Clarence Mak, as well as other Hong Kong, American and German composers. It will include special lighting effects, dancers and actors to create a full multi-media programme. One of the highlights of the festival is a South American programme next Tuesday - modernised tangos and new trios by Argentine composers including Astor Piazzola and Daniel Binelli, performed by Grupo Encuentros from Buenos Aires. On Sunday October 15 there is a concert by Hong Kong's only percussion ensemble, playing music by John Cage, Joshua Chan and other composers, while on Wednesday October 18 and Friday October 20 there will be two different all-Chinese concerts with new music from Beijing, by the Eclipse Ensemble from the Central Conservatory. The festival ends with an appearance by Swedish oboist Helen Jahren, who will perform with the Hong Kong Sinfonietta on October 22, premiering an oboe concerto by local composer Hui Cheung-wai. Musicarama Festival concerts are at City Hall at 8pm. With the exception of the Argentine programme, which costs $60-$120, all tickets are $60.