Every time I walk across the Vivian Beaumont stage, on a day when there’s no performance of My Fair Lady, my eye gravitates to the bulky device that Higgins uses to teach Eliza how to speak properly. What, I wondered this week when making such a stroll, is that heavy-looking piece of machinery? And where was it found?

To satisfy my curiosity I emailed Alison Mantilla, the props supervisor for the show. “To find it,” she said, “I had to dig deep on research and figure out how people would have recorded and listened to sound in the homes during the early 1900s.” There weren’t a myriad of choices. Only Edison, Mantilla said, had a machine that did both – the phonograph. “You could change the needle,” Mantilla went on, and that “would hit the wax cylinder. There was one needle for recording, and one needle for playback.”

Edisons haven’t been manufactured in decades, so where did Mantilla find such a machine? Some dusty antique store in Queens or Brooklyn? Hah! She found it on eBay. “The particular one we have,” she said, “is a 1906 Thomas Edison Home Phonograph. We then altered it so it would still rotate, but not play any record in particular.”

As My Fair Lady’s sound expert, Marc Salzberg, informed me, that was not the only alteration. The contraption was designed for the home, not to fill a Broadway-sized theater. The machine, Salzberg said, is “such a beautiful antique that I did not want to butcher it to put speakers in, so there are wireless speakers on the shelf below it.”

For you technical nerds, Salzberg was more precise. “There’s an in-ear monitor (IEM) receiver, a battery-powered amplifier, and a speaker on that shelf. The sounds themselves are played from a computer using a program called QLab, and transmitted to the IEM.”

QLab? IEM? If Higgins and Eliza were alive today, their lessons would be virtual, and Eliza’s busting-out number would be called “I Could Have Skyped All Night.”

Brendan Lemon is the editor of lemonwade.com