2x2

Harmony is the blending of simultaneous sounds of different pitch or quality, making chords. Melody is the rhythmical combination of successive sounds of various pitch, making up the tune. With four members each, these perfectly balanced bands are able to use the variety of vocal qualities to create some beautiful music together.

Abba	Mammas and Pappas	The B52s
Little Big Town	Four Non Blondes	Ace of Base