Okuda Hiroko

The "rock" preset is not usable at a normal rock and roll tempo (around 172 bpm). Only when the tempo knob is turned down to the 80-110 bpm range, home to reggae and dub, does it become possible to play an accompaniment to the "rock" preset. Okuda only learned of her part in "Under Me Sleng Teng"'s global success in August of 1986, when she read an article titled “The Sleng Teng Flood” in Japan's Music Magazine. The article described the wave of dozens and dozens of reggae songs being produced in Jamaica, all based on a Casiotone keyboard preset.

Okuda Hiroko (奥田 広子) is the Japanese inventor and musicologist who, at the start of her career in 1980, composed the rhythm and bass preset backing tracks included in Casio's electronic keyboards. These included the "rock" rhythm, which became the ubiquitous Sleng Teng Riddim, heralded the Ragga movement, and has since underpinned hundreds of hit reggae songs. Okuda and Casio have allowed her backing-rhythm work to proliferate under a free attribution-only license, which have contributed to their popularity and widespread use. She holds more than a dozen patents in the fields of electronic musical instruments and presently works at the intersection of electronic music and visual art.

Okuda joined Casio in April 1980, immediately upon graduation from music college. Her first assignment was to develop six two-bar rhythm and bass preset backing tracks which would be used in the Casiotone Casio MT-40 and Casio's other contemporaneous keyboards. The six styles were "rock," "samba," "disco," "waltz," "swing," and "pop." The "rock" style was soon to be made famous in Jamaican dancehalls. The MT-40's "rock" preset, along with the keyboard's suggested 1/16 note fill for that preset, formed the basis of Wayne Smith and King Jammy's 1985 reggae hit "Under Me Sleng Teng", which went on spawn nearly 500 cover versions. This song's success is widely credited with single-handedly transitioning reggae from analog to computerized production. The preset is accessed by pressing the "synchro" button and then the "D" bass button (second from left) while the MT-40 rhythm slider is in the "rock" position. Although the original MT-40 was only produced for about a year, and its "rock" rhythm was retired with it, its ongoing popularity led Casio to bring it back in 2010 in their SA-46 and SA-76 keyboards, this time under the name "MT40 Riddim".

Okuda, a pianist from childhood, became a fan of British rock music in middle school, and this developed into a deep interest in Jamaican reggae in the 1970s. Okuda attended a musical high school, and then Kunitachi College of Music, where she studied musicology with an emphasis on Reggae, the topic upon which she wrote her graduation thesis. While a college student in 1979, Okuda attended several of Bob Marley's concerts, on his only visit to Japan.

After the worldwide success of Sleng Teng many speculated as to the ultimate source of the "rock" preset. At first Eddie Cochran's 1958 song "Somethin' Else" or the Sex Pistols' 1976 track "Anarchy in the UK" were thought to be prime candidates, with "Somethin' Else" being widely accepted for decades by connoisseurs. In 2015 Okuda was quoted as saying the source was a track on an unnamed 1970's British rock album. This was later speculated to be the intro to David Bowie's "Hang On to Yourself", the 8th track on his 1972 album The Rise and Fall of Ziggy Stardust and the Spiders from Mars. However, referring to the question in 2022, Okuda said, “I did use to listen to a lot of British rock, so I’m sure there must have been songs that influenced me. But really, the bassline was something I came up with myself. It wasn’t based on any other tune.”