A German engineer hunting for a cheaper cigarette trim and Bing Crosby seeking a lighter workload helped set the stage for the Magnetophon laugh track. The path wound through interwar laboratories, Nazi propaganda studios, and postwar Hollywood editing bays, with the Magnetophon tying the story together.
What Was the Magnetophon?
The Magnetophon was a high-fidelity reel-to-reel magnetic tape recorder developed by AEG, with tape supplied by I.G. Farben, and it drew acclaim at the Berlin Radio Show after its 1935 debut. Its origin traces to Fritz Pfleumer, a Dresden inventor who in the early 1920s sought a cheaper way to mimic the gold band on premium cigarettes.
He swapped gold leaf for powdered bronze on paper, then later imagined replacing that metal powder with a magnetizable coating to record sound on paper tape.
Pfleumer, familiar with wire recording pioneered in 1898 by Valdemar Poulsen, patented his “sounding paper” in 1928 and built a companion recorder. The early results were fragile and noisy, but the medium offered two breakthroughs.
It could be cut and spliced for edits, and it could be erased and reused.
To commercialize the concept, Pfleumer partnered with AEG in 1932. AEG board chair Hermann Bücher backed the effort and enlisted his colleague Wilhelm Gaus at I.G. Farben.
AEG developed the machines and I.G. Farben refined the tape. The Magnetophon was supposed to debut at the 1934 Berlin Radio Show, but the launch was pulled two days before the event.
By 1935 the system was ready, and interest surged. AEG fielded requests for variations, including telephone integration, playback units for prerecorded content, and a version adding artificial reverberation for open-air recording.
Iterations over the next three years culminated in the Magnetophon K4 in 1938, the first commercially successful model.
The K4’s leap came from AC bias, which added a high-frequency signal, typically 40 to 150 kilohertz, to reduce distortion and hiss, especially in quiet passages. Its fidelity was so high that radio audiences often could not tell taped performances from live broadcasts.
The Magnetophon During and After the War
Adolf Hitler and propaganda minister Joseph Goebbels exploited radio’s reach, and the Magnetophon became an asset for messaging and military deception. Because recorded speeches could air with live quality, broadcasts could originate from one city while Hitler was elsewhere, complicating Allied efforts to track his movements.
Wartime isolation and disrupted information flows long obscured the Magnetophon’s capabilities in the United States. Records show, however, that AEG’s Schenectady affiliate received a Magnetophon in November 1937 and demonstrated it to General Electric engineers, who dismissed it.
Wider recognition in America came only after the war.
U.S. Army Signal Corps officer and electrical engineer John T. “Jack” Mullin heard German “live” orchestral broadcasts during the war that lacked the usual surface noise of transcription discs. Convinced Germany had superior recording technology, he located Magnetophon units at a radio station as the war ended.
In 1945, Mullin returned to California with two disassembled machines, tape, schematics, and a plan to reshape U.S. audio production.
Bing Crosby Championed the Magnetophon Laugh Track
By the mid-1940s, Bing Crosby was radio’s dominant star but chafed at performing two live shows each week to accommodate time zones. He wanted to prerecord, yet the surface noise of transcription discs gave away the illusion and NBC refused.
Crosby sat out a season and then joined ABC, which agreed to let him record for later broadcast.
At the same time, Mullin was demonstrating the Magnetophon in California. In October 1946, Crosby’s technical producer, Murdo MacKenzie, arranged a demonstration at the Metro-Goldwyn-Mayer studios.
Crosby embraced the potential and invested 50,000 dollars in Ampex, which partnered with Mullin to engineer an American version. Mullin became Crosby’s chief engineer, and 3M produced the tape.
In 1947, Crosby became the first major U.S. radio star to prerecord weekly shows. Beyond the machine’s fidelity, Mullin’s razor-and-tape edits stitched together multiple takes into seamless performances.
During one session, a guest delivered a joke that was too risqué to air, but the audience’s reaction was golden. Producers began cataloging laughs, from gentle chuckles to booming guffaws, and editors could sweeten a flat gag by inserting the perfect reaction afterward.
Crosby’s daughter Mary later said he accepted this approach, caring that the jokes worked regardless of the live audience’s response. Mullin’s daughter, Eve Mullin Collier, recalled that her father disliked manufacturing mirth, uneasy with editing joy into existence.
Technology often yields unintended outcomes. Mullin admired the Magnetophon for preserving authentic moments and labored to perfect it for listeners.
Yet the same precision enabled canned responses and a new production grammar. He helped usher in the era that made the Magnetophon laugh track possible, even as the use drifted beyond his intent.
An abridged version of the original article appeared in the August 2026 print issue under the title “Birth of the Laugh Track.”
For another look at how everyday experiences are shaped by technology and history, see our feature on American colonists health in 1776.