For 17 weeks in the spring of 1969, an unusual recording sat atop the Billboard pop music chart. Eventually spending a year in the top 200, Wendy Carlos’ “Switched-On Bach” was the first classical album to go platinum, selling more than 500,000 copies. Glenn Gould, the Canadian pianist world-renowned for his own interpretations of Bach, called it “one of the most startling achievements of the recording industry in this generation and certainly one of the great feats in the history of keyboard performance.”

The album’s cover explicitly juxtaposed old and new: A prim Bach look-alike in a blue brocade coat and curly wig holds a controller connected via wire to a black apparatus bristling with knobs and a keyboard resting on a prim doily. Marrying technological innovation with the conventions of classical music, “Switched-On Bach” brought electronic music into the mainstream — along with the Moog synthesizer that Carlos used to create the album.

First produced in 1964 by Robert Moog, the machine in short order became a fixture in experimental and rock compositions, though it had yet to gain the widespread recognition it would later enjoy. Moog himself — his name rhymes with “vogue” — had no talent as a musician, though he had long loved electronic music and its instruments. Growing up in Queens, N.Y., he built his first theremin in 1949, when he was 15 years old. The theremin, developed by inventor (and sometime NKVD technologist) Léon Theremin in the 1920s, used two oscillators to control pitch and volume. Requiring no physical contact from the user, the instrument relied totally on the amplitude and voltage of radio waves to create its ethereal tones. Simply moving your hands near its metal antennae modulated the warbling, wailing sound it produced.

By the age of 19, Moog had set up (with his father’s aid) R.A. Moog Co. to sell theremin coils, do-it-yourself theremin kits and completed instruments. By the time he had arrived at graduate school, as a physical engineering student at Cornell, he was supplementing his funding by building the kits in his landlord’s basement and selling them for $50 a pop.

Through his theremin business, Moog befriended tuba manufacturer Walter Sear, who convinced Moog to attend the New York State School Music Association gathering at the Eastman School of Music in the winter of 1963. There, Moog met music engineer Herb Deutsch, who was immediately intrigued by Moog’s technological expertise. Part of New York’s burgeoning experimental music scene, Deutsch invited Moog to come downtown to hear his “Contours and Improvisations for Sculpture and Tape Recorder,” which combined real-time percussion created by banging metal sculptures with recorded tape. Moog was wowed by the strangeness of the performance, and offered his help in future endeavors. Deutsch told Moog of his desire for a portable electronic music studio, adding, “I want to make these sounds that go wooo-wooo-ah-woo-woo.”

Settling in Trumansburg, a small town near Ithaca, Moog got to work. At the time, cheap silicon transistors were becoming more widely available. Noticing that transistors allowed him to change pitch electronically by altering the voltage, Moog created a mechanism that paired the input of one volt with a change in pitch of one octave. Like the theremin, the new machine used two oscillators to create a loop of feedback that ping-ponged pitches back and forth. The “Moog” (perhaps following Theremin’s lead, Moog bestowed his own last name on his machine) then used subtractive synthesis to turn this complex waveform into a sawtooth, triangle, pulse or sine wave — each with its own distinctive sound.

After the newly formed Moog Company — which would also produce theremins and electric guitar effect pedals — secured a grant of $16,000 from the New York State Small Business Association, Moog solicited feedback from Deutsch, a committed avantist, as well as from more conventional composers. Their responses resulted in modifications to his initial prototype, and the invention of the Attack-Decay-Sustain-Release (ADSR) envelope, a generator that allowed the user to control each sound’s onset, intensity and fade.

Collaboration, indeed, was key to the Moog’s success. The final machine was produced through “innovation rather than invention,” as Trevor Pinch and Frank Trocco write in “Analog Days: The Invention and Impact of the Moog Synthesizer.” Even after Moog sold his first machine to choreographer Alwin Nikolais at a 1964 conference of the Audio Engineering Society’s conference in Manhattan, he continued to listen to input about its modular aspects. One of Moog’s most important collaborations was with Wendy (then Walter) Carlos. Carlos, a transsexual refugee from academia, urged Moog to incorporate a conventional touch-sensitive keyboard and a portamento control that would allow voltage generated by one key to slide to the next. He also suggested that Moog include a fixed filter bank with each commercial machine.

No matter what make of Moog you wanted, it did not come cheap. Three different models ranged in price from $2,800 to $6,200. Despite — or because of — its high cost, the Moog became a key instrument of countercultural sound, part of any good experimental composer’s bona fides. John Cage used it in compositions for Merce Cunningham. Jazz musician Sun Ra and his Arkestra drove the band’s fleet of Cadillacs to Moog’s workshop. Mick Jagger frolicked with a Moog in the 1968 film “Performance.” (That particular machine eventually was sold to a Berlin recording studio, where it influenced a generation of German electronic music.) By 1968, acts as disparate as The Byrds, Stevie Wonder, Frank Zappa, The Beach Boys and the Beatles had all used the Moog in studio recordings. The Moog Company could hardly keep up with orders.

All this success carried with it some pushback. Studio musicians feared that synthesizers could put them out of business; the American Federation of Musicians briefly banned the machines, at least until the union created a new professional category, “synthesizer player.” The synthesizer wasn’t just another instrument; it changed the way composition, performance and recording were both executed and perceived.

When Moog and the newly rechristened Wendy Carlos premiered “Switched-On Bach” at the New York Audio Engineering Society in October 1968, it received a standing ovation. As the centuries-old composition came to life via cutting-edge technology, the audience perhaps recognized the transcendent nature of the music being played, as well as the endless creative possibilities inherent in this strange new instrument. Small wonder the Moog became an icon of the electronic age.