TO THE delight of opera fans, the Urban Council will present the popular three-act opera La Traviata next month. Based on the novel La Dame Aux Camelias, by Alexandre Dumas Fils, it is a love story with a tragic ending of a young courtesan, Violetta, and a young man of good family, Alfredo. Their love affair is opposed by Alfredo's father, who fears that the relationship will ruin Alfredo and his sister's marriage prospects. Set in the fashionable Paris of the 1859s, the opera's music is appropriate to its subjects - not heroic, not passionate, not bombastic, but vivacious, gracious and gentle. La Traviata is produced by Lo King-man. Directed by Tim Coleman with Paul Nadler and Long Yu as conductors, a brilliant cast of internationally renowned vocalists will join hands with the Hong Kong Opera Society Chorus, the Hong Kong Ballet and the Hong Kong Sinfonietta, to give five performances at the Cultural Centre Grand Theatre from September 20 to 24. The opera will be performed in Italian with English and Chinese titles. Tickets at $500, $380, $280, $150 and $80 with half price for students and senior citizens are available at all Urbtix outlets. Call 734-9009 for reservations.