We know D.C. Get our free newsletter to stay in the know.

How did you spend your summer vacation? Minimalist composer Richard Chartier spent his in the basement of the Museum of American History. For three months, starting in June, Chartier recorded the “Grand Tonometer,” a four-octave instrument built by German physicist Rudolf Koenig from 1870 to1875. Recording each of the instrument’s 660 tuning forks from strike to decay was a painstaking process, one that required Chartier to do daily battle against noisy ventilation systems and women clacking down halls in high heels.

In a live performance at the Hirshhorn tonight at 7 p.m., Chartier will mix those recordings with sounds from other 19th century instruments in the debut of his new composition, “Transparency.”

“I come from a digital music background, so I’m used to working with sounds that are very precise sine waves,” says Chartier. “These tuning forks are very precisely tuned, but there’s a physicality about them…There’s a warm feeling to the sound. At the same time, it’s unsettling.”

Unsettling is also a good description for Chartier’s music, which denies listeners the familiar foothold of melody and rhythm. Instead, Chartier’s pieces use sustained sounds that change ever so slightly over long periods of time. The reward for patient listening: a heightened awareness of the inner structure of sound.

Chartier’s goal, incidentally, is similar to that of the Grand Tonometer’s inventor. Koenig used the instrument to demonstrate the concept of beat frequencies—-the pulsing you hear when two pure tones that are very close in pitch are played simultaneously. The physicist toured Europe with his instrument, attending society gatherings and trying to persuade audiences that sound is a wave rather than a particle.

At his performance, Chartier won’t be lecturing about physics. He will, however, be working with sounds from real instruments for the first time. The final product, says Chartier, may be more approachable than his previous, purely digital, work.

“It’s more musical, in a way,” he says. “It has a linear, almost narrative, flow.”

That said, audiences may have trouble focusing on the minimalist composition for its full 50-minute run time. Chartier’s advice: “Just kind of let it flow over you. Just zone out. I have had people fall asleep during my shows before. As long as they don’t snore, I’m fine with it.”

A Grand Tonometer