We have a lot more than just music for which to thank Swedish supergroup Abba. Impresario Cameron Mackintosh says he couldn't have undertaken his £35 million refurbishment of London's West End without them. Or, to be more precise, without Mamma Mia!, the musical fashioned around their greatest disco hits such as "Thank You for the Music", "Dancing Queen", "Take a Chance on Me" and the show's title song. The blockbuster has been packing them in since April 1999 at Mackintosh's Prince Edward Theatre, where its grossed more than £80 million and been seen by more than 2.5 million people. Speaking at yesterday's press conference to announce renovations to seven West End theatres and the creation of an eighth, the 500-seat Sondheim Theatre (See News, 25 Jun 2003), Mackintosh said: "That show has been a fantastic boon for a theatre-owning novice. If I hadn't had such an enormous hit in that theatre, I don't think I would have been able to do this." Mamma Mia! is currently booking at the Prince Edward up to 22 May 2004. After that, Mackintosh confirmed yesterday, it will transfer to his Prince of Wales, reopening the theatre which has just closed for a £7 million refurbishment.