JANOS Starker is a virtuoso cellist, stylistic visionary, inventor, mentor and lecturer - and age does not seem to weary him. The rising 69-year-old is on tour, playing at the Cultural Centre on Friday, and has released six albums in the past two years. The Hungarian emigre was a child prodigy but first came to international notice in the mid-1950s in New York when he recorded four of the six solo suites by Bach, setting new standards for performance and establishing his reputation as a soloist with particularly rich tonality. As a touring performer, Starker has played in virtually every corner of the world, first appearing in Hongkong in 1960. And because he also teaches music and has written extensively on the subject, the cellist is a much sought after mentor for up-and-coming players. In conjunction with his concerts, Starker often holds seminars while out on the road. He has also made a contribution to musical technology wi th the ''Starker Bridge'', an innovation which dramatically improves the quality of sound for stringed instruments. ''I asked for conical shaped holes to be drilled into the seat of the bridge,' said Starker. ''It acts like a small pre-amplifier so to speak. So the sound goes through a little hole before it hits the body of the instrument.'' He is touring with American-based pianist Shigeo Neriki. The two have a close working relationship, both being music professors at the Indiana University School of Music. ''He's Japanese but he lives in Bloomington next to me,'' said Starker. ''He's an outstanding pianist and he travels with me all over the world. ''It's a very special relationship. He's like my son and his son is almost like my grandson. We're like members of the same family.'' Although much of Starker's repertoire is derived from the classics, he is not averse to investigating newer material. To this end, Starker has recorded compositions by several contemporary composers, including Bernard Heiden and Miklos Rosa. His performance in Hongkong, however, is intended to be a decidedly crowd-pleasing affair with pieces by Beethoven, Brahms, Schubert, Bartok and Falla. Janos Starker appears with Shigeo Neriki at the Hongkong Cultural Centre Concert Hall on Friday at 8 pm.