The gala, directed and produced by Oscar-nominated film director Zhang Yimou , consists of eight parts, with the first five devoted to China's ancient civilisation and the rest to highlighting the country's contemporary history.

Zhang Heping, director of the Beijing Organising Committee for the Olympic Games' opening and closing ceremonies department, said more than 15,000 people would go onstage, one-third from the military.

After the theme song is performed, athletes will march into the stadium behind their national flags. Then there will be an address by officials and the Olympic flag will be brought into the stadium.

In all, 29,000 fireworks shells will be fired, half of them inside the stadium. The ceremony will close with the lighting of the Olympic flame, but Mr Zhang gave no clue as to the identity of the final torch-bearer, saying only that he or she had been chosen based on 'sporting achievement' and 'social influence'.

Bocog launched a four-year global appeal for a theme-song melody and lyrics in 2005 and promised to unveil it before the Games.

Music professionals said the choice of singers was fitting.

'Liu Huan's tonality is stout and strong, and he is also well cultured in literature and the arts,' pop-song writer Chen Tong said. 'And Sarah Brightman's voice is crystal-clear and rich in penetrating power.

'Moreover, Brightman can shift freely between the classical and modern expressions of music. So the [duet] will be a merger of oriental and western music styles.'

Song Meng, a deputy research fellow in aesthetics with the China Academy of Arts, said: 'Sarah Brightman commands a very wide spectrum of tonality. Liu Huan has a profound understanding and accurate grasp of music. Moreover, Liu's sound is very touching and passionate, and so quite suited to expressing the current mood of Chinese people in an Olympic celebration.'