It’s easy to take music technology for granted in the year 2022. We are nearing a century of music synthesis, and access to electronic sounds both new and old has never been easier, or more affordable, for the average hobbyist. Entire genres of music have been shaped by specific synthesis applications, many of which include participating musicians born after the genre’s peaks in popularity. To Gen-Z, sounds from Pink Floyd’s EMS synth arpeggios in “On the Run” or  Public Enemy’s screeching siren samples in “Terminator X” are all considered oldies. With a resurgence of widespread interest in synthesizers from the late 20th century, new styles have emerged with unique interpretations of the synthesized sounds of the 80s, and 90s, such as synthwave and vaporwave. It’s crucial for contemporary artists seeking to reapproach the electronic sounds of the past to know the full story behind not only the instruments they love, but their inventors and the theories they put into action to create these powerful machines.

One particular device that helped provide the foundational sounds for entire decades worth of popular electronic music was the Yamaha DX-7.

The first affordable commercial synthesizer of its kind, the DX7 provided a new means of combining synthetic waveforms to create unique timbres never heard before by the average musician. This new synthesis technique was known as Frequency Modulation, or FM, synthesis, and its inventor is a composer and Stanford professor named John Chowning. Most have heard the sounds of FM synthesis, whether they be seasoned musician or the casual listener, while very few know the unique story behind the sounds and what would become John Chowning’s primary legacy.

Chowning, born on August 22nd, 1934, studied composition under a wide variety of mentors and styles, including the monumental French pedagogue Nadia Boulanger. He earned his Doctorate of Musical Arts in composition from Stanford University in 1966. It was during this period that Chowning began experimenting in the field of computer music and digital synthesis, a relatively new academic field compared to the study of analog electronic musical interfaces.

While innovations in analog synthesis in the mid 20th century brought us new sonic circuitry implementations, such as the ability to combine multiple oscillators in sequence with one another (amplitude modulation), the introduction of voltage-controlled filters (subtractive synthesis), or the ability to allow one oscillator frequency to control that of another (ring modulation), there were many aspects within the analog circuitry that John Chowning found impossibly limiting for the sonic theories he sought to implement. There were only so many instrumental timbres and waveforms that Chowning felt he could design without the use of a computer; analog circuitry meant sonic instability and chance encounters that he sought to avoid.

The introduction of 1960s digital signal processing allowed Chowning to experiment with a continuation of ring modulation synthesis through the combination of three unique oscillators’ functions, known as the modulator, carrier, and operator, which allowed for incredibly complex and unique waveforms to be generated through the combination of simple sinewaves. Through these early experiments in frequency modulation, Chowning was able to determine specific ratios between the three oscillators that emulated familiar acoustic instruments, such as brass, mallet percussion, and strings. This algorithm of recalling specific modulator, carrier, and operator settings would be finalized in 1967 through the support of Stanford, who would not allow the patent to be used for commercial purposes for a standard 8 years after its development.

In 1974, Stanford allowed Chowning to sell the rights of the FM algorithm to Yamaha corporation and to begin working directly for the company, proving to be one of the most lucrative patent sales of the 20th century for Stanford. In 1977, Chowning composed one of his most famous compositions to demonstrate the timbrel capabilities of FM synthesis through a series of colliding longtone combinations titled Stria.

While Yamaha’s first commercial use of FM synthesis was demonstrated through the GS1 in 1981, it proved to be a commercial failure due to its steep price. In 1983, Yamaha reintroduced Chowning’s FM algorithms in a sleek, smaller, and more affordable keyboard controlled synthesizer: the DX7. Chowning’s algorithms were used to create easily accessible instrument presets on the DX7, allowing smaller studio operations to create fully orchestrated ensemble productions of familiar sounds for a fraction of the cost and time it would take to record it with live musicians.

Through this revolution efficiency, the DX7 would go on to help define the 80s and 90s pop sound, being featured significantly in countless international Top 40 hits, including the main synth hook from A-Ha’s “Take On Me”, the synthetic marimbas from Toto’s “Africa”, the bass line to Michael Jackson’s “Smooth Criminal”. The DX7’s versatility in allowing for the user to patch their own sound design algorithms through their own combinations of modulator, carrier, and operator ratios, which became crucial for experimental artists such as Brian Eno in the development of Ambient music. Looking at modern examples like Toro y Moi’s Boo Boo and Aphex Twin’s midimutant project the instrument remains a staple in the synthesizer community for both veterans and vintage gear enthusiasts alike.

John Chowning knew he struck gold when he first developed the algorithm for FM at Stanford in 1967, and he continues to advise the Yamaha synthesis R&D team to this day as they further expand his research in the 21st century. He remains the type of composer and sonic innovator that we can all aspire to be, to constantly seek new means of sound design to unearth timbres the world has yet to hear.