The composer Joseph Bertolozzi, bearing a meditative look, stood with his feet apart in front of a door frame inside the Eiffel Tower. Then, 57 metres above the Champs de Mars garden, he pulled a latex mallet from his tool bag and hit the frame hard, and then softer, with agility and rhythm. "That one was beautiful!" said Paul Kozel, a sound engineer, who recorded the dull thuds.
Bertolozzi, who lives in New York, is in Paris harvesting sounds for what he calls a "public art installation", a musical project that has taken him, Kozel and a team of seven to one of the most visited monuments in the world.
His mission is to "play the Eiffel Tower" by striking its surfaces, recording their sounds and using them as samples for an hour-long composition called Tower Music. He hopes for a live, on-site performance of the work to celebrate the tower's 125th anniversary next year.
"I'm exhilarated to be here," Bertolozzi said, before striking a wall with a sheepskin-padded log hanging from a leather strap. "I've been planning this for so long."
Knowing no French and lacking contacts in Paris, Bertolozzi has spent more than four years on his quest. He raised $40,000 from private donors and convinced the Eiffel Tower administration that he was a legitimate musician.
"Improbable" yet "extraordinary," Jean-Bernard Bros, the president of the Eiffel Tower operating company, said of the project, which he called "exceptional because it is rare, it is unique".
Bros, however, was noncommittal about allowing a live performance. "Let's see first what the sounds produce - the fruit of his effort," he said.
As outlandish as Bertolozzi's project seems, it is part of a long-standing tradition of percussion works produced by found objects. One example is Magnus Lindberg's Kraft, scored for orchestra and percussion "instruments" found in local junkyards, such as brake drums and wheel rims, and performed in recent years by the New York Philharmonic. This time the object happens to be a giant monument in a European capital, but it is not the first large structure from which Bertolozzi has created a work. He also composed Bridge Music, a piece consisting of sounds culled from the Franklin D. Roosevelt Mid-Hudson Bridge, near Poughkeepsie, in New York state.
On the second day of a two-week expedition that started in May, Bertolozzi and his team had already recorded about 400 sounds. He struck girders, spindles and handrails with drum sticks, wooden dowels, Lucite mallets and rubber hammers, some of his own design.
"We see if the sounds have a pitch relation, like do re mi," Bertolozzi said. "The different dimensions of the Eiffel Tower give you different notes." For instance, "if you have a big panel, it will vibrate slower and longer, so you'll produce a deeper pitch, usually". The vertical shape of the tower, he said, "gives you a great number of resources if you need high notes, middle notes, low notes."
Bertolozzi said he originally felt some anxiety. "If I find 500 B flats on it, then what am I going to do?" he said. "But we're doing great. We're finding all kinds of notes."
The idea of playing on the Eiffel Tower struck Bertolozzi, an organist who also collects gongs, after his wife mimicked him striking a gong one day nearly a decade ago. "She 'banged' at the Eiffel Tower on a poster hanging on the wall of our bedroom," Bertolozzi said. "I thought, 'This would work."'
At the time, the Eiffel Tower seemed a stretch, so he turned his efforts to an instrument closer to home. "I knew Gustave Eiffel was a bridge builder, so I said, let me do something on a bridge here in America," Bertolozzi recalled.
The result, Bridge Music, was released in 2009 and reached No. 18 on the Billboard classical crossover charts. He could not find money for its live performance, but local authorities installed a permanent listening station on both sides of the bridge, where visitors can hear samples from April through October.
In preparation for his Parisian experiment, Bertolozzi studied the design of the Eiffel Tower. He listened to the works of French composers such as Ravel and Poulenc, whose pieces have elements of cafe music and street sounds. The tower, too, serves as "a deeper inspiration for me to try to find new ways of creating sounds," he said.
During his note-gathering, some tourists seemed a little puzzled, but the tower's staff found Bertolozzi's approach coherent and unsurprising.
Stephane Roussin, the chief engineer of the tower, said the structure made noises and vibrations. "It whispers," he said with a smile. "We often bang on it to make sure that the material isn't defective."