ABBA were a merger of two married couples - Anni-Frid (Frida) Lyngstad and Benny Andersson, Agnetha Faltskog and Bjorn Ulvaeus - who not only went on to become the 1970s' biggest pop phenomenon, but captured the imaginations of succeeding generations. They first made it big winning the 1974 Eurovision Song Contest with Waterloo, as memorable for their outrageous costumes as the incessantly frothy music. They confounded those who dismissed them as one-hit wonders with a string of brilliantly crafted Number 1 hits, including S.O.S, Take A Chance On Me, Super Trouper, Knowing Me Knowing You, Thank You For The Music and Dancing Queen, written by Benny and Bjorn. Tensions within the band arose as both marriages collapsed and, though they never officially split, they stopped working together in 1982. Benny and Bjorn wrote the Chess musical with Tim Rice and the ABBA legend was cemented by the Mamma Mia stage show and movie, which introduced their music to new audiences.