1) ABBA and Kiss 2) Boyz ii men and others 3) Musical groups 4) Sets of four 5) The Beatles et al 1) Fours 
[card game] Quartets is a card game, similar to Go Fish, which was the start of Top Trumps. The game was invented in the Netherlands where it is known as `kwartet`. They were originally created by Austrian card game company Piatnik during the 1960s., but later began being released by Dubreq, Ace, Waddingtons and other companies. Quartets, l...