Anthony Agnello’s Harmonizer Brought Recording Studios Into the Digital Age

The Life Member receives a Lifetime Achievement Technical Grammy Award

16 April 2018

Anthony Agnello was 23 years old when he stepped inside the basement that was then the office of Eventide—an audio hardware company just starting out in New York City. It was 1972 and he was looking for a job.

Agnello was pursuing a master’s degree at the City University of New York, where he was studying digital signal processing at a time when music was produced by—and recorded exclusively on—analog equipment. That day he met one of the company’s founders, Richard Factor, and they began what would become a lifelong partnership. During the course of four decades, they developed digital audio devices for recording, broadcasting, and film.

Their work is being recognized with this year’s Lifetime Achievement Technical Grammy Award, to be awarded in July. The Grammy Awards, presented by the Recording Academy, recognize achievement in the music industry.

When The Institute asked Agnello what the recognition means to him, he joked, “It means that I’m old.” He says he was fortunate because the timing was right. “If not for Richard and I, someone else would have done it.”


Agnello came from a musical household, and knew he wanted to somehow combine music and technology. “If I were more talented or braver, for that matter, I might have become a musician instead,” he says.

As Eventide’s first engineer, he invented the H910 Harmonizer, which could alter sounds from instruments as they were being recorded in the studio. That allowed musicians and producers to incorporate new techniques into their works, such as changing the pitch of an instrument, delaying a sound, or having a sound repeat with a feedback loop. Agnello calls it the “first digital effects box.”

Before the H910, studios got crafty with makeshift mechanical tools to simulate or delay sounds during the recording process. The H910 was far more effective and versatile.

Two floors up from Eventide was a recording studio, where Agnello tested his invention by recording his own music and inviting family and friends to do the same. When Jon Anderson of the band Yes got wind of the Harmonizer prototype, Eventide sent it to him to experiment with.

By 1975, the Harmonizer was being displayed at audio technology conventions. At the time, it was the only digital audio effects device for recording studios, Agnello says. Hundreds of musicians started using it, including David Bowie, John Lennon, and Frank Zappa.

To Agnello’s surprise, broadcasters were using the Harmonizer to adjust the pitch of audio. One TV broadcaster sped up the audio of “I Love Lucy” reruns to squeeze in more commercial time.

Perfecting the device did have its challenges, such as how to change the pitch of an audio signal without changing the tempo—seemingly impossible at the time, Agnello says. He also figured out how to digitally simulate acoustic spaces, what’s known as artificial reverberation.

Agnello developed a general-purpose array processor, the SP2016, to host his reverb algorithms. In addition to reverb, the SP2016 could handle a wide range of new effects including “vocoding” to synthesize voice, chorusing to combine multiple sounds into one, and granular synthesis, in which sounds are broken up to form other sounds.

The processor allowed for several types of unnatural reverberation. Phil Collins of Genesis, for example, used gated reverberation to make his drums sound more powerful. New effects could be “plugged in” using ROM chips, heralding the advent of software plug-ins.

“Humans have a visceral reaction to music,” Agnello says. “By providing musicians with a broader palate to work with—new, innovative ways to manipulate sound—music can communicate ever more complex emotions.”


As the years passed, Agnello continued to develop algorithms, which now are deployed in dozens of products including electronic pedal boards and plug-ins that the company sells.

In 2015 Agnello collaborated with Tony Visconti, who had produced most of David Bowie’s albums, to create a software emulation of the studio techniques that Visconti utilized in some of Bowie’s most iconic works.

Last year the company released a patent-pending technique that makes it possible to separate parts of a single sound—such as from a hit of a snare drum—into its tonal and transient components. The technique was introduced in the Netflix show “Stranger Things” to make the snarling sound of a monster.

“We create tools,” Agnello says, “and when these tools get into the hands of artists, we’re amazed at the creative ways in which they’re used.”

Although the Grammy is for his lifetime of achievement, Agnello says, “No part of me feels that I am done.” At 68, he is managing director at Eventide and says he absolutely loves what he does. He advises others not to get stuck in a job that’s not rewarding.

It’s a big world out there, he says, and career opportunities are everywhere—including at Eventide, which is currently hiring developers. In his spare time, he produces the expurgated Gear Club Podcast, where world-class audio pros talk about the art and science of recording.

IEEE membership offers a wide range of benefits and opportunities for those who share a common interest in technology. If you are not already a member, consider joining IEEE and becoming part of a worldwide network of more than 400,000 students and professionals.

IEEE membership offers a wide range of benefits and opportunities for those who share a common interest in technology. If you are not already a member, consider joining IEEE and becoming part of a worldwide network of more than 400,000 students and professionals.

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