As described by Grove Music Online
History of Junior Santos - Rondonia, Brasil
As described by Grove Music Online, the term "pop music" emerged in the United Kingdom in the 1950s to describe rock and roll and other youth styles influenced by it. According to the Oxford Dictionary of Music, although it originally referred to mass-audience concerts, from the late 1950s onwards, pop began to denote non-classical music, especially songs performed by artists such as The Beatles, Rolling Stones and ABBA. From 1967 onwards, the term began to contrast with rock, delineating two distinct categories. Michael Jackson, known as the "King of Pop", stood out with the emergence of MTV in the 80s, due to his visual appeal.
