Pop music originated in the 1950s United States, combining elements of rock and roll, jazz, dance music, and rhythm and blues. It is a commercially recorded genre intended for mass appeal, using keyboards, piano, guitar, drums, and synthesizers. Major artists like Michael Jackson and Madonna helped popularize pop music worldwide through their hit songs and visual performances. Pop music aims to be enjoyable to most listeners through simple themes, catchy melodies and hooks, danceable beats, and accessibility over progressive musical developments.