Mr. Moog’s original 1964 synthesizer  he called it the Abominatron  was bulky, balky and sometimes unpredictable. It was analog, not digital, creating sounds by sending a continuous electronic signal to a speaker, not a stream of numbers through a converter. To analog devotees that continuous signal is intrinsically superior to digital music, which reproduces sound with tens of thousands of samples per second, which means tens of thousands of infinitesimal gaps between them. Analog sound, said Amos Gaynes, Moog Music’s applications engineer, has infinite resolution, “down to the granular level at which reality is perceived.”

The first commercial Moog synthesizers could play only one note at a time, not always in tune. Early synthesizer users had no preset sounds to fall back on: they plugged in patch cords, turned knobs and experimented. A musician could create a sound, but the synthesizer had no memory; once the sound was changed, it was gone, possibly forever. Heat and humidity also affected the instrument. When digital synthesizers arrived, in the 1980s, sales and prices plunged for those primitive analog synthesizers. They seemed destined for obsolescence.

But not so fast. From their sometimes-unstable oscillators, filters and amplifiers, Moogs and other analog synthesizers produced sounds that more reliable digital synthesizers would not: buzzes, swoops, whooshes, scrapes, gurgles, screeches, burps, crackles and countless other onomatopoeia-worthy noises. Interactions among the waveforms that were generated by the oscillators, and modulated by waveforms from other oscillators, or from a noise generator, were often untamed. Turning a knob or wiggling a wheel on the Minimoog could radically change a timbre in mid-note, making it feel more handmade, less synthetic. Analog sounds are a funky corrective to sterile digital tones; colliding waveforms make a beautiful noise.

Moogfest was a festival of strange sounds and monumental beats, of drones and loops, and of synthetic tones that grew to feel natural. For extra oddity a good part of the audience wore Halloween costumes all weekend.

Neon Indian’s wistful pop marches emerged from thickets of staticky synthesizer noise and disappeared back into them. Panda Bear, from Animal Collective, sang high, chantlike melodies over unswerving synthesizer and guitar drones in what came to sound like cries from the heart. Omar Souleyman, from Syria, sang heartily about love and street life over booming 4/4 drumbeats, while his keyboardist simulated traditional Middle Eastern instruments on two synthesizers. Emeralds played one continuous, very gradually unfolding song, with Moog sounds rippling and percolating through it.