Reggae music evolved from earlier Jamaican genres like mento and ska. In the 1940s, sound systems played American R&B and jazz music to attract patrons in Kingston, and this eventually became the main entertainment. In the 1960s, producers like Coxsone Dodd and Prince Buster began experimenting with accentuating the offbeat in the music, which helped define the ska genre. Ska gained popularity in Jamaica and abroad. Rocksteady emerged in the late 1960s with slower tempos and prominent electric bass. This eventually evolved into reggae in the late 1960s, characterized by slower tempos, new studio effects, and prominence of Rastafari ideology and Jamaican drumming styles.