The Riddim Economy: One Riddim, Many Voicings

The music that followed Sleng Teng in 1985, built on programmed keyboards and drum machines rather than a band in a room. It made records cheaper and faster to produce, which put them within reach of far more people, and it changed the sound completely — harder, drier, and rhythmically freer than anything a live rhythm section had been playing. Almost every Jamaican record since is downstream of it.

William Maragh, billed the Wild Apache, born in the Cockburn Pen area of Kingston also known as Seivright Gardens, of Jamaican and Indian descent. His debut album Si Boops Deh! in 1985 carried "Boops" — the word entering Jamaican speech for a man who keeps a younger woman — and established a delivery that was faster, more rhythmically intricate and more melodically inventive than most of what surrounded it. Don Dada in 1992 took him to a US major and into the New York hip-hop orbit, where he worked with the Notorious B.I.G., Heavy D and Puff Daddy, and made him one of the handful of Jamaican deejays American rap treated as a peer rather than a novelty. He has recorded sparingly since.

Tenor Saw (born Clive Bright, 1966-1988) was a Jamaican dancehall singer widely considered one of the most influential vocalists of the early digital reggae era. Working with Sugar Minott's Youth Promotion and the Black Roots label, he recorded hits including "Pumpkin Belly" and "Fever," but is best remembered for the 1985 anthem "Ring the Alarm" on the Stalag riddim. He died in Houston, Texas, in 1988 after being struck by a car.

A small consumer keyboard sold from the early 1980s, and the most consequential piece of equipment in dancehall's history. One of its preset accompaniment patterns — slowed down and reworked by Noel Davey — became the rhythm of Wayne Smith's "Under Mi Sleng Teng", produced by King Jammy in 1985. A machine intended for living rooms replaced the session band, and the music has been made on keyboards ever since.

"Under Mi Sleng Teng," Wayne Smith's 1985 recording produced by King Jammy over a Casio MT-40 preset riddim, is widely credited as the record that pushed Jamaican music from live-band production to computerized digital riddims almost overnight, spawning close to 500 different versions.

The singer of "Under Mi Sleng Teng" (1985), the King Jammy production whose Casio-driven rhythm is the conventional starting gun for digital dancehall. Smith (1965-2014) recorded plenty besides, but the record that changed the music's economics — no session band required — is the one history keeps him for.

The practice that organises Jamaican music: a rhythm track is not used once but voiced repeatedly, by different artists, across years or decades. A riddim is a shared commons — competing, answering and building on one another over the same bed. It is why the archive is threaded with version chains rather than isolated records, and it has no real parallel elsewhere in popular music.

The 1985 riddim, built by Wayne Smith and Noel Davey on a Casiotone preset at King Jammy's and voiced by Smith as "Under Mi Sleng Teng", that ended the era of the live band as the default of Jamaican music. Cheap, fully electronic and instantly copyable, it triggered the digital turn: hundreds of versions followed within a few years, production costs collapsed, and dancehall's tempo, texture and economics were remade around it. Nothing else in the archive divides a before from an after so cleanly.

Arthur "Duke" Reid's studio above his liquor store at 33 Bond Street, Kingston, and the label of the same name. If Studio One owned ska, Treasure Isle owned rocksteady: from 1966 Reid's productions with Alton Ellis, the Techniques, the Paragons, Phyllis Dillon and John Holt defined the slower, sweeter, bass-forward form, and those rhythms became a second foundation catalogue — the basis of countless later versions, not least through U-Roy toasting over them in 1970.

Lloyd James, the engineer and producer who came up under King Tubby in Waterhouse and then changed the music twice over. He built and ran his own sound before turning to production, and in 1985 issued "Under Mi Sleng Teng" — the Casio-preset rhythm that ended the live-band era and opened the digital one. Through the late 1980s his Waterhouse studio was the busiest room in Jamaica, cutting for Half Pint, Admiral Bailey, Chaka Demus, Ninjaman and most of the era's voices, and his Super Power sound carried the same material into the dance.

How a cheap keyboard preset in 1985 reset the sound of dancehall.

In the studios of 1970s Kingston, engineers learned to dismantle a finished song and rebuild it as something stranger, launching the version, the remix and the idea of the producer as author.

When King Jammy's went digital in 1985, a wave of deejays rode the new Waterhouse computer sound into the dancehall mainstream.

The digital riddim turned the producer into the star of the record - and the story runs from a Casio preset to the modern hit factory.