Casio Keyboard Programmer Retires After 45 Years: The Story of Hiroko Okuda

Hiroko Okuda is a Japanese inventor, musicologist, and electronic music developer whose work reshaped reggae and digital music. Her most famous creation is the “rock” rhythm preset for Casio keyboard, the MT-40, which became the basis of the “Sleng Teng” riddim—a turning point in Jamaican dancehall. Her story bridges Japanese engineering, musical passion, and global cultural impact.

Early Life and Entry into Casio

Okuda was born in Nagasaki Prefecture and showed an early interest in music. She developed a deep love for British rock and Jamaican reggae. In college, she wrote a thesis on reggae, an unusual choice at a time when most students focused on classical traditions. After graduating, she joined Casio as its first employee with a music college background, at a time when Casio was branching out beyond calculators into electronic instruments like keyboards.

At Casio, her first task was working on preset rhythm and bass tracks for new Casio keyboard products. She worked with a team of developers with musical training, and she stood out for her familiarity with popular genres. Early on, Okuda composed six rhythm styles (rock, samba, disco, waltz, swing, pop) with bass lines corresponding to various chord types. It was in this context that her “rock” preset, later known as Sleng Teng, would emerge.

Sleng Teng and Global Impact

The “rock” preset on the MT-40 Casio keyboard later caught the attention of Jamaican artists, notably Wayne Smith, who turned it into “Under Mi Sleng Teng” (1985). That song helped launch subsequent versions all built on that same underlying rhythm, making “Sleng Teng” a “monster riddim” in dancehall history. Over 450 tracks have been traced to it—the preset transformed reggae from live-band recording toward digital, keyboard-based production.

Although many knew Sleng Teng’s roots among reggae aficionados, Okuda avoided public exposure for decades. She rarely gave interviews and remained personally anonymous in media discussions. It was only in recent years, as her role gained more recognition abroad, that she began to accept interviews and public appearances. Okuda’s design became the backbone of a musical revolution that extended beyond Japan and shaped the legacy of Casio keyboards.

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Methods, Patents, and Later Projects

Okuda’s method was technical and musical. To turn rhythmic ideas into usable presets, she converted musical notation into code, recorded it into ROM, and tested it via hardware prototypes. This was laborious, especially under the limited memory capacity and sound channels of early keyboards. She focused on constraints, sound limits, length, and note count to make rhythmic and bass lines that felt musical yet were compact.

Throughout her career, she registered patents in areas such as automatic accompaniment, rhythm-playing apparatus, tonality determination, and performance information processing. Later, she led or contributed to projects that merged music and visuals, which transformed performance input into real-time visual output. These were a part of her lifelong mission to make music more accessible, expressive, and interactive.

Retirement and New Directions

On July 20, 2025, Hiroko Okuda officially retired from Casio after nearly 45 years of service. This milestone came as she had begun preparing for post-company life, including granting interviews and reflecting publicly on her work. At Casio, she had been the company’s first female developer and one of its first music-college graduates, all marks of her pioneering role.

In retirement, Okuda plans to work on the ideas she was unable to develop fully at Casio. She expressed interest in small-scale, creative projects that might be difficult for a company. In addition, she wants to continue working with electronic instrument design, music-visual systems, and new forms of artistic expression, such as through her Music Tapestry concept. She hopes to transform how people engage with music beyond traditional performance.

Why Her Influence Is Important

Hiroko Okuda’s influence extends far beyond one preset or product. By blending musical intuition with electronic design, she revolutionized the way music was created, transforming a studio process into something anyone could produce at home with a Casio keyboard. Her Sleng Teng rhythm lowered barriers for artists, making professional-quality music accessible through affordable keyboards. This helped launch a revolution across global pop and electronic genres.

Her work highlights the quiet yet significant role of Japanese engineering in shaping the world of music. Casio’s instruments became platforms for creative freedom due to developers like Okuda. Her combination of precision, curiosity, and openness to other cultures set a model for how technology can foster artistic exchange.

Even after retirement, her ideas continue to influence music software, rhythm programming, and cross-cultural collaboration. Have you ever heard of Sleng Teng? Did you know about the history behind it? Let us know in the comments below!

Cited Sources

• Nippon.com. “‘Sleng Teng’ Riddim Creator Okuda Hiroko Retires from Casio, Looks to the Future”.
• YouTube. “Sleng Teng Riddim Mix Pt. 1.“
• The Asahi Shimbun. “Casio employee is creator behind reggae ‘monster of rhythm’ beat“.