Okuda Hiroko

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.

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.

[5] 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".

[11] 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.

It wasn’t based on any other tune.”[12] Okuda has said that she had in mind to create a drum-and-bass line which would be easy to "toast" over, and attributes much of the success of the backing track to its simplicity, which allowed musicians to flexibly layer many types of compositions over it.

Toshio Kashio in particular felt strongly that the company's mission ought to be “bringing the pleasure of playing a musical instrument to everyone.”[9][13] Despite the minute size and financial importance of the Musical Instrument division compared to the company's calculator division, then its main breadwinner, Toshio Kashio's defense of free use set a decisive corporate precedent.