Benny Andersson ... "By the way, the Abba reunion needs a fifth person! Hi, it can be me, I can do the backing vocals!" Michael Ball said having to learn his character's chess moves for the ...

Abba's two leading men made a surprise appearance as hit musical Mamma Mia! celebrated its 20th anniversary in London's West End. Huge applause welcomed Benny Andersson and Bjorn Ulvaeus onto the ...