We don't hear a lot about ABBA anymore, unless they do the "70s special" on the radio. ABBA's music did make a bit of a comeback because of a movie called "Mamma Mia".
The group was 2 guys and 2 beautiful girls. They were Benny Andersson, Björn Ulvaeus, Anni-Frid Lyngstad (usually known as Frida) and Agnetha Fältskog.
Best of all, the two girls were a lot of fun to look at, specially singing "Dancing queen".