Robert Moog, one of the most important figures in the foundations of electronic music and experimental media, died on Sunday at the age of 71. Here is an appreciation of his work and life, by Jon Pareles, printed in the New York Times.
Switched On and Ready to Rumble - New York Times: An Appreciation

By JON PARELES
Published: August 23, 2005

Unintended consequences always delighted Robert Moog, the inventor of the synthesizer that revolutionized music who died on Sunday at 71. He realized he could create a musical instrument by fine-tuning the controls for oscillators. There had been electronic instruments before; Mr. Moog was drawn to the Theremin, and started building his own version of it. But the Electronic Music Module prototype he introduced in 1964 was far more imposing than the Theremin, and far more flexible.

The Moog's first incarnations were banks of knobs and connectors for patch cords to make oscillators interact. Working with composers, Mr. Moog conceptualized a musical note as something with three variable components: a basic tone, filters that would alter the timbre, and an 'envelope' governing its attack, sustain and release: whether it was a sharp percussive impact or a tone that could float in, wax and wane, and slowly fade out. Separate modules, each with its own bank of knobs, governed each component, and the slightest twist of a knob could radically alter the sound that emerged.

Unlike current synthesizers with preset sounds, the first Moogs had none; musicians arrived at the sounds they would make by trial and error and intuition. If they liked a sound, it was best to get it on tape immediately, because for all its knobs and switches, the Moog was a difficult instrument to control. It wasn't easy to go back to a previous timbre once a knob had been touched even slightly. But from that balkiness came remarkable new sounds.

The Moog could have stayed that way: a generator of abstract noises and effects, good for a sci-fi swoop or a low rumble. But musicians asked Mr. Moog for a keyboard so they could easily play melodies once they found a sound they liked. Mr. Moog added one; after all, it was just a different kind of interface. 'Switched-On Bach,' recorded with an early keyboard-controlled Moog, made his name and instrument famous in 1968, even if it was a bit out of tune. Musicians also wanted an instrument smaller than a refrigerator, and the Minimoog and Micromoog were rugged enough to be used onstage.

They were analog synthesizers, pitting oscillator against oscillator in combinations that never had entirely predictable results. They were great for glissandos, able to slide completely smoothly (digital synthesizers go by increments). They also made some very nasty noises: snorts and bloops, buzzes and shrieks with an edge. Musicians liked those sounds precisely because they were unruly. They could cut through a mix, and even though the Moog was monophonic - just playing one note at a time - it caught on.

Soon Moogs were everywhere, making sounds that were as startling as they were unnatural. A Moog was essential to songs like 'Here Comes the Sun' by the Beatles and to albums like Stevie Wonder's 'Music of My Mind.' In 1977, Bernie Worrell used a Minimoog to play the swampy, viscous bass lines on Parliament hits like 'Flash Light': a sound that has been the foundation for countless funk and hip-hop songs.

Mr. Moog had listened to musicians who wanted something portable that would generate the same sound twice. But he didn't let his synthesizer become simply a different kind of electric organ: a collection of preset sounds each available by pressing a button. He clearly loved sounds that could wobble and timbres that could shift on a whim. The Minimoog still used knobs and made musicians choose which oscillators and modifiers they wanted in which proportions. It also included a pitch wheel that could be wiggled to bend notes at will, making pitch yet another uncertain variable.

Digital synthesizers - in which the same numerical input always yields the same thing - came along with sleeker, more manageable sounds, and soon dominated the market. But affection for analog synthesizers, and the Moog in particular, persisted: in hip-hop, in collegiate rock (where the likes of Beck and Radiohead pride themselves on their analog sounds), and wherever musicians want something that's electronic but impolite. The Minimoog itself came back as the Minimoog Voyager, adding a new batch of preset sounds to the old analog controls and filters. Now the fat, savage tones concocted by patient knob-twisting in the 1970's are available readymade.

When synthesizers first appeared, they were denounced because they would supposedly remove the human touch from music. Mr. Moog's instruments weren't about the microgymnastics of touch and timing that are involved in playing a piano keyboard expressively. But they depended on other musicianly skills: a willingness to experiment, the luck necessary to make those wayward analog components align in useful ways and the ear to know when a sound is right. Mr. Moog's instruments were ornery and unstable, but rich in unexpected possibilities. It's no wonder musicians found them irresistible.