Sunshine pop

Sunshine pop is a certain type of pop music, most often characterized by a cheerful attitude, harmony singing, and sophisticated production, although there is no formal or strict definition.

This music peaked from the mid-1960s to early 1970s, but subsequently faded into obscurity. However, since the 1990s Sunshine Pop has experienced a remarkable revival which continues until the present day.

Source : http://en.wikipedia.org/wiki/Sunshine_pop