WHERE is the most comfortable place for a singer to hold a concert? Certainly not 303 metres under the sea! But UK pop singer Katie Melua did just that. The 22-year-old and her five-member band played for workers on a gas rig (钻油平台) in the North Sea earlier this month. And she entered the Guinness Book of Records for performing the world's deepest underwater gig (演唱会)...