the musical Bjorn Ulvaeus and Benny Andersson wrote with Sir Tim Rice, is being revived in the West End. Will Abba's new music ruin their legacy? Abba give first performance in 30 years 6 shocks ...

Abba songs were "were all written in the very same way," he said. "The two of us in a room banging away, suddenly something coming up. "Some of the songs there must have been years between them ...