The advent of rocksteady came in 1966, a few years after the Jamaican independence. It is a derivative of ska and laid the foundation for the creation of reggae, which is today one of the world's most popular music forms.
One theory behind the creation of rocksteady is that it is named after a popular song, "Rock Steady" by Alton Ellis. It differs from ska in that it has slower tempo and there is more emphasis on the bass and was so named because when you heard music you stood in one place and rocked steadily. The ska-style back beat and the emphasis on the offbeat carried over into rocksteady.
The Rude Boy social element in Jamaica at the time heavily influenced the lyrics in rocksteady, which were typically about romance and the rude boy life style. Songs such as '"No Good Rudie" by Justin Hinds & the Dominoes; "Don't Be a Rude Boy" by The Rulers, and "Girl I've Got a Date" by Alton Ellis, were popular rude boy rocksteady songs.
Rocksteady only lasted for about 2 years before Reggae became the dominant music in Jamaica.