Russian billionaire Andrei Melnichenko asked the star to sing for his wife's birthday partyJennifer Lopez has been paid a staggering UKP1 million by a Russian billionaire to perform at a private concert.Andrei Melnichenko has asked the Latin star to put on a 40-minute show at his wife Aleksandra's 30th birthday party tomorrow night (21.04.07).Melnichenko is paying UKP600,000 for the performance and a further UKP400,000 to fly J.Lo's entourage from the US to Britain where the party will take place.The bash will take place in the Berkshire countryside although J.Lo and her entourage will stay in a top London hotel which is included in the UKP400,000 payment.A source close to the singer said: "Andrei and Aleksandra are huge fans of J.Lo and were thrilled when she agreed to sing for them. It will be an unusual audience for J.Lo, as the bash will be packed with billionaires."The party, which will take place in a marquee decorated like a plush nightclub, will be an extravagant occasion, with the all-day event including a cabaret and circus act.This is not the first time the couple - who count Chelsea football club's billionaire owner Roman Abramovich among their friends - have splashed out on a celebrity performance.When they married in 2005, they paid a reported UKP2million for Christina Aguilera to sing at their wedding in the South of France.