Not many pop groups end up on postage stamps, as Abba has in its native Sweden; but then again, few groups become their homeland's most identifiable export. The group's stratospheric success was built on a foundation of buoyant, exquisitely arranged and produced pop music. Although they called it a day in the early 1980s, Abba lives on in the form of popular tribute bands and albums, a Broadway musical, and consistent record sales of their voluminous catalog.