Abba: In Performance.

In this video critique (which includes archival concert footage), experts and insiders discuss the legacy of Swedish sensation Abba -- who burst onto the pop scene in the 1970s and quickly became one of the world's most commercially successful bands. With such catchy tunes as "Dancing Queen" and "Waterloo," combined with marketing smarts that led the group to record in several languages, Abba remains popular long after disbanding in 1983.