ABBA

The most commercially successful pop group of the 1970s, ABBA put Sweden on the map as a music mecca and influenced the sound of pop for decades to come. With their flamboyant fashion sense and two-couple membership, the quartet also became pop culture icons. However, it was their distinctive harmonies and intricate production (combining folk, pop, rock, and even classical) introduced on songs from their 1973 debut album, Ring Ring, that won them countless fans. It's a sound that garnered the first Swedish win at Eurovision in 1974 with "Waterloo," the title track from their s...