Aside from its technicolor glow and killer power, the lightsaber’s most notable characteristic is its distinctive, low-pitched hum. Over at The Atlantic, Adrienne LaFrance sheds light on the mastermind behind the iconic buzz: a sound designer named Ben Burtt, who was interviewed about his brainstorming process in a Star Wars video extra a few years back.

Burtt’s inspiration stemmed from his years as a projection booth operator at the University of Southern California’s School of Cinema-Television (now School of Cinematic Arts). As a graduate student receiving his master's degree in production, he noticed that the booth’s old Simplex Projectors made “a wonderful humming sound” when they were connected to the system with an interlock motor.

“It would slowly change in pitch, and it would beat against another motor—there were two motors—and they would harmonize with each other,” Burtt said.

The sound was soothing, but it needed some punch. Burtt found the missing element by accident: While recording something, he left the microphone on. He passed a muted TV set, and the microphone picked up its transmission and started to whine. Burtt recorded the sound, combined it with the noise he’d heard in the projection booth, and voilà—the lightsaber’s basic hum was born. Later, Burtt added force and motion to the sound by waving a microphone in front of the air next to the speaker, layering the pitch shifts into the pre-recorded sound.

Learn more about Burtt’s creative process—and the seminal Star Wars weapon—in the video above.

All images courtesy of YouTube. 

[h/t The Atlantic]