Within strolling distance of the train station bearing the name of their first global hit, Swedish band ABBA celebrated 40 years of pop success to mark their groundbreaking song Waterloo.

Two of the four members of the band that made spangled jumpsuits and big boots a trademark attended the bash at the trendy Tate Modern museum on Monday night, marking four decades since their catchy tune won the Eurovision song contest in April 1974 and launched them into international stardom.

Bjorn Ulvaeus, who wrote many of the group’s songs with ABBA co-founder Benny Andersson, said he was stunned by the rise and rise of ABBA even after it effectively disbanded in 1983.

ABBA, from left: Bjorn Ulvaeus, Agnetha Faltskog, Anni-Frid Lyngstad and Benny Anderson.