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Waterloo, the winning entry in the 1974 Eurovision Song Contest, featured Benny Andersson as a key contributor. Andersson, a member of the Swedish pop group ABBA, co-wrote the song with Björn Ulvaeus and Stig Anderson. The song's catchy melody and upbeat lyrics helped it become a global hit, solidifying ABBA's status as one of the most successful pop groups of all time.