An opera singer's life is like a series of hurdles - never more so than in a Hong Kong summer which offers its own peculiar challenge. Outside, the temperature on Tsim Sha Tsui's waterside promenade is 34 degrees Celsius, the atmosphere heavy from the penetratingly high humidity. It is, according to the weather forecast, the hottest day of the year. Yet a few steps away in one of the Cultural Centre's rehearsal rooms, it is a chilly 17 degrees and noticeably drier. Soprano Karen Notare, one of the two female leads in Verdi's Aida - this year's opera presented by the Urban Council - is markering, or avoiding testing her voice to its limit. Having flown in from an engagement in temperate Dublin, the weather has been on her mind. She rolls her eyes skyward in acknowledgement, with a 'tell me about it' grimace. 'This climate can play havoc with your voice and sinuses,' says the Italian-American, who counts winning the prestigious Puccini Foundation Award three times among her achievements. 'It's hell coming from the outside into air-conditioning then back again. And then there's the mould and mildew. I've changed my hotel room three times already. 'But I wouldn't be anywhere else. This is going to be totally amazing.' Cynics may dismiss this as the exaggerated talk of a self-important diva acting the drama queen. But they would be wrong. Aida, as aficionados will testify, ranks as a particularly demanding opera for singers - both in terms of its vocal range and its phrasing. Regarded by many as Verdi's greatest and arguably most popular composition, it, like Urbco's Turandot last year, is a grand opera, as extravagant in its exotic ancient Egypt setting as it is intoxicating in its rich musical output. It marked a departure from Verdi's previous works in which the singing dominated, to compositions where the vocal lines, still expressive and melodious, were more closely related to the psychology of the characters and their motivations. Verdi also demonstrated his mastery of promoting variety: from the subtle characterisations of individual roles to grand crowd scenes, and from intimate emotions to the dramatic mass climax. And unlike his efforts such as Rigoletto in which solos, duets and ensembles give the impression of being linked together, Aida 's elements are seemingly inextricably bound to one another. 'This is theatre at its greatest - it's a visual spectacle on the scale of a Cecil B DeMille epic,' Notare says. 'Here you have one man and two women who love him. It's like something out of a soap opera like Dynasty or Bold and the Beautiful. That's why it is so easy to relate to.' At the opera's heart is the daughter of the king of Ethiopia, Aida, who personifies the contrasts that are the hallmark of the opera. The Ethiopian princess is captured by the Egyptians, and made the slave of Princess Amneris; both fall in love with the Egyptian army commander, Radames. Inevitably, it leads to tragedy with one the winner - but at a terrible price. 'Aida has enormous vulnerability yet she is a tigress,' says Notare, regarded as one of the most distinguished artists of today. 'She can also play situations but is big hearted.' As Notare explains, such a role demands vocal technique. 'There are a lot of pianissimo [very quiet] phrases that are complex,' she says, pointing out that of all the roles she has played perhaps only that of Norma, from the opera of the same name by Bellini, ranks as more difficult. Wang Yanyan, who shares the part of Aida with Notare and is playing it for the first time, agrees: 'It's very pianissimo on top. It can be very dangerous singing this kind of role. 'Your voice has to be very mature to sing it. A lot of people push too hard and then find they fail,' she says. She has spent three months preparing for the part. 'I've been cautious. You have to get used to Verdi's power and his melodies - to develop the technique.' One of her weapons is to 'eat well and sleep well'. 'I sleep at least eight hours a day. It's only when you're asleep that your vocal chords are completely relaxed,' Wang says. Notare draws on past experience to look beyond the part, treating it as an organic process, adding: 'The marvellous thing is you can pour your heart out and no one will ever say it's too much because that's what the audience wants.' But she admits what is difficult about Aida is that it is so emotional. 'You can't allow yourself to get too immersed otherwise you end up crying. 'It's like a race card. You know each twist and turn but you're on a madcap ride. You have to be on the ball.' Tenor Warren Mok, who shares the part of Radames with Li Yuxin, is playing the male lead for the first time. With a twinkle in his eye, he says it is Aida 's heroics and strong melodies that appeal to him. 'Aida is one of my favourite operas,' he says. 'I find the role very special. It's been done by the famous tenors like Jose Carreras and Luciano Pavarotti. If you haven't done Aida you're not a tenor. 'I've been practising for two months and my voice feels very comfortable.' For Lo King-man, the producer and director, the organisation of this grand opera has been his greatest challenge. 'You cannot have one cast, you have to choose two separate but balanced ones,' he says. Scrutinise some of the components and you glimpse what he means: 130 extras, 96 in the chorus, and 75 in the orchestra pit . . . the list goes on. '[Because of numbers] for the first time we are using the Grand Theatre up to its maximum depth,' he says. Yet despite the grandiosity, with what promises to be stunning sets evoking ancient Egypt with their hieroglyphics, he hopes to take a different approach from Aida productions in recent years which emphasised the vocally and visually spectacular. 'I want to go back to what Verdi felt and observe all the niceties of expression and feeling,' adds the director, simply.