Short answers, pulled from the story.
Dancehall originated in Kingston, Jamaica, in the late 1970s among lower and working-class communities in the inner city. The genre was not officially named until the 1980s, when Michael Tomlinson of InnerCity Promotions staged a concert series that gave the emerging music its identity as 'DanceHall.'
A riddim is a pre-recorded instrumental track over which multiple artists record different sets of lyrics. The riddim 'Real Rock,' first recorded in 1967, was used in at least 269 songs by 2006. Most dancehall songs in the genre's peak years were set to one of roughly a dozen popular riddims at any given time, according to Peter Manuel and Wayne Marshall.
Shabba Ranks was the first dancehall artist to win at the Grammy Awards. His debut album 'As Raw as Ever' won in 1991, and his second album 'X-Tra Naked' in 1992 earned him back-to-back awards along with multiple Billboard chart positions for singles including 'Ting-A-Ling' and 'Mr. Loverman.'
Sean Paul's 'Get Busy' (2003), from his album 'Dutty Rock,' was the first dancehall single to reach number one on the US Billboard Hot 100.
Sound systems were the primary way dancehall music reached audiences, since conservative radio stations refused to play the genre. Because many Jamaicans could not afford home radios, the mobile, high-volume sound systems brought music directly to inner-city communities. The success of the music depended on the DJ, the Selector, and the Sound Engineer working together.
King Jammy's 1985 production of 'Under Me Sleng Teng' by Wayne Smith, built around a Casio Casiotone MT-40 keyboard, is widely credited as the first entirely digital rhythm in reggae. The 'Sleng Teng' rhythm was subsequently used in over 200 recordings. The Casiotone MT-40 and the Oberheim DX drum machine became foundational instruments in the new sound, producing faster tempos and a synthesized texture.