But in order to breathe, music relies on a certain amount of flexibility, on the skill of a performer to toy with the tempo in ways that molds a phrase or throws into relief the emotional trajectory of a piece. The question of how to balance precision and freedom, accuracy and interpretation has always vexed musicians. With the invention of the metronome it became more acute. An underlying theme of the exhibition, Ms. Münzner said, is “how much of your inner life you bring into music.”
The earliest guides to pacing a piece of music were internal, personal and subject to fluctuations — chief among them the human pulse. By the 18th century a common tempo marking was “Andante,” Italian for “walking.” Others, like “Tempo di Minuetto,” referred to particular social dances. But even more often pieces of music were merely marked as “slow,” “quick” or “grave.”
For some composers and theorists this was frustratingly vague, and beginning in the 17th century came attempts to link musical time to the motion of a clock. Around the same time scientists discovered that the length of a pendulum affects the speed of its motion, with a pendulum of just under one meter swinging at one second each way. Instrument makers seized on this to build musical timekeeping devices in which the length of a pendulum is adjusted according to specific gradations to make it swing at a desired speed.
One example on show is the English “Balance Regulator” by Rudolph Ackermann from 1812. It’s one of the earliest pieces in the comprehensive collection of metronomes by the British instrument dealer Tony Bingham, which forms the bulk of the Basel exhibition. (The show has been extended through January 2018.) Pendulum-based timekeepers were silent — offering only visual guidance — and relied on distance units, which varied from country to country. To a musician in Italy, the markings in inches on Ackermann’s “Regulator” would have been of little use. And to mark slower speeds, a pendulum had to be lengthened to unwieldy proportions — over two meters for 40 swings per minute.
In 1814 a watchmaker in Amsterdam, Nikolaus Winkel, came up with a breakthrough. His “musical cronometer” still featured a pendulum, but its point of suspension was now moved to the middle of a rod, with a weight at either end. By moving one of the weights along the rod, closer or farther away from the fulcrum, the oscillation speed could be precisely controlled. Even very slow speeds could now be achieved on a portable device.
Winkel sent his invention to the Dutch Institute of Sciences in 1815 for assessment. But in the meantime he had made the acquaintance of Johann Nepomuk Maelzel, a pianist and builder of mechanical music machines from Vienna, who had been developing a pendulum-based timekeeping device of his own.
According to David Fallows, who wrote the introduction to the exhibition catalog, Maelzel “immediately recognized the technical and practical advantages of Winkel’s instrument and offered to buy the design.” Even though Winkel refused, Maelzel soon after filed for, and was granted, a patent in Paris for what he called a “metronome” — combining the Greek words for measure and rule — adapted from Winkel’s design.
A British patent followed. By the end of 1817, the instrument was in use across Europe and composers including Beethoven were marking the speeds of their compositions with an MM number indicating the number of beats per minute as produced on a “Maelzel Metronome.”
In a phone interview Mr. Bingham shed doubt on a famous anecdote according to which Maelzel sent 200 metronomes for free to as many composers. “That’s a complete fabrication,” he said. “There’s no contemporary account of it at the time, and it would have been a big thing. If you look at Maelzel as an entrepreneur, he had a very up-and-down life. He couldn’t have afforded to fabricate 200 instruments and give them away.”
Still, Maelzel’s marketing skills — he also placed anonymous endorsements of his own product in newspapers and pressured composers to add theirs — ensured that his metronome became an integral part of musical culture. Even so, Mr. Kirnbauer, the curator, said silent pendulum-based timekeepers continued in use well into the 20th century. Bartok used one during his field research into Hungarian folk music.
Non-musicians also adopted the ticktocking metronome. Mr. Bingham’s collection includes an enormous pyramid-shaped “army preceptor” built in London around 1840 that was used in military drills. It has three speeds: slow, quick and double-quick. Medical researchers adapted metronomes for experiments on the nervous system, for use in therapy with Parkinson’s patients and stutterers. Dubious products in the late 20th century included a “New Relax Machine” to be placed on the solar plexus, and a device for self-hypnosis. Pavlov’s famous dog learned to salivate to the ticking of a metronome.
By then musicians had developed a testy relationship with the device. That was because the metronome quickly outgrew its original intended use. At first, the purpose was to allow a composer to clearly indicate the tempo at which a work was to be played. The performer would listen to a few ticktocks to note the desired speed and then turn off the device to play or sing.
But soon pedagogues seized on the metronome’s potential to act as taskmaster and conductor in the absence of a teacher, advising students to practice scales and entire movements to the audible mechanized beat. This was contrary to the natural flexibility of tempo that had been self-evident in musical performance for centuries, the little eddies of halting or rushing motion that lend life and flow to music.
Brahms, who rarely wrote down metronome markings in his autographs, said he did so only when “good friends have talked me into putting them there, for I myself have never believed that my blood and a mechanical instrument go well together.”
Sebastian Currier, who was the composer-in-residence at the recent Chelsea Music Festival in New York, which also had as its theme “Measuring Time,” said in an interview that “there has to be one unwritten strata” in any composition. Still, he said he was content with the convenience of using metronome markings to set the initial conditions of a piece: “The flexibility you have to gain from the music.”
In the 20th century, technology made it ever easier to regulate the production of sound, with electronic music allowing for perfectly even pacings. Click tracks became common in performances, especially of Minimalist music, with musicians fitted with an earpiece that delivered a steady beat.
On the other end of the spectrum were composers like John Cage, many of whose compositions transcend the need for a metronome: His famous, silent “4’33” requires no subdivision into beats.
The Basel exhibition explores some of the more rebellious responses to the metronome in a room that features the instructions for Ligeti’s “Poème Symphonique” for 100 metronomes, a work that scandalized a Dutch audience in 1962 because the timekeeping devices were the sole instruments. There’s also a video of the orgiastic scene in Fellini’s “La Prova d’Orchestra” (“Orchestra Rehearsal”) from 1978 in which the irate musicians attack a tomb-size metronome.
Today, computers have learned to simulate the tiny irregularities that the human ear is drawn to in music. Recording engineers put computer-generated music through a process of “humanizing” that delays the beat by a few milliseconds. In that sense a quote by the 18th-century composer and flutist Johann Joachim Quantz seems prophetic:
“With skill a musical machine could be constructed that would play certain pieces with a quickness and exactitude so remarkable that no human being could equal it either with his fingers or with his tongue,” he wrote. “Indeed it would excite astonishment; but it would never move you.”
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