Voice Tunnel: The New Yorker "The experience of being in a place you're not allowed is already so special that you could throw some rubber bands in the corner and the installation would look great," the Mexican artist Rafael Lozano-Hemmer said about the Park Avenue tunnel. The seven-block-long subterranean roadway, in midtown, was closed to traffic and open to pedestrians for the first time in its hundred-and-seventy-nine-year history. Lozano-Hemmer had lined the blackened stone that buttresses the tunnel with a hundred and fifty speakers, and lit the tunnel's corrugated-metal roof with three hundred spotlights, as a work of public art. The problem with this tunnel is what not to do - there are just so many possibilities. Lozano-Hemmer's "Voice Tunnel," which opened this past Saturday and will continue for the next two, invites visitors to record a short message through an intercom at the passage's midpoint. The recording is then looped through speakers on either side of the intercom. The amplification triggers the spotlights, two to each speaker, to flash according to the intensity of the voice, illuminating the ridges of the tunnel's arched roof. As each visitor adds his or her voice, the previous recording and its translation into light are pushed outward, down the length of the tunnel and toward its edge, until the flood of new messages supersedes it. Every minute or so, the spotlights extinguish, and the tunnel returns to darkness, punctuated only by the diffuse, ghostly light from air vents overhead and at the tunnel's northern egress. Lozano-Hemmer's intentions for the project are, he said, "utopian" and "idealistic." "One of the things I most want is for this piece to profile the way that New York is made up of an incredibly vibrant mosaic of different cultures," he told me, ticking off his inspirations: free speech, using your voice - "one of the beautiful things about voice is we all have one." He swoons at "ideas of representation, plurality, diversity." Instead, on Saturday, thousands of visitors and would-be speakers came to experience the tunnel's novelty. "I walk by here every day and I came just to see the tunnel," said a young man who lives on Thirty-fifth Street. Actually, it's sort of hard to hear what's going on. He paused. I'll take the light show. "Voice Tunnel" certainly stimulates the senses. A man picked up a call on his iPhone only to plug the other ear and yell into the receiver, "I can't hear you!" Most people walked into the tunnel, phones drawn, to photograph the tunnel, and themselves in it. Lozano-Hemmer admitted that the volume was too high. If someone whispers on the microphone, I want that to come through. Engineers were working to dial down the bass frequencies and amplify the higher, quieter frequencies of a child's voice, or a woman's. "It annoys me that the guys are louder," Lozano-Hemmer added. A line of New Yorkers and tourists, some with canes, others with strollers, still others with tripods for the photo op, snaked down the center of the tunnel, waiting to record a message. One woman, visiting from D.C., said the project's message of personal expression fit perfectly with a "personal journey I've been on for the past six weeks." What message from that journey would she share? "I'm just going to say, "Freedom!" " She beamed. Her companion was less thrilled. They had been in the tunnel about twenty minutes, and his eyes hurt from the flashing lights. For his turn at the intercom, "I think I'm just going to make some noises," he mumbled. One of the favorite refrains about New York is that much of what is outlandish or vibrant about the city is only possible there - or that, in a place so dense and diverse, those qualities take on unique proportions. Janette Sadik-Khan, the commissioner of the Department of Transportation, which organized the project, boasted, "New Yorkers are never shy in expressing their opinion, and that's certainly true today." ("This kind of thing only happens in New York" is one of the messages I heard. Another, "This is too early for New Yorkers," contradicted the evidence: visitors were lined up at 6:45 A.M.) Foreign languages could be heard amid the cacophony: German, Spanish, Croatian, something else Slavic-sounding that I couldn't identify. Laura Chang, a college graduate living in the city, was in line with her mother, a native Mandarin speaker, and a friend, Divya Lakhati. Chang loved how free, interactive art can make you feel like a tourist in your own city. Lakhati's message, when she recorded it, would be "Best city ever." But was the tunnel a New York moment, or merely a chaotic scene of flashing, beeping public art? Individual messages were inchoate, enthusiastic, kitschy, joyful, sarcastic. I love New York! I am awesome. He-e-e-re's Johnny! I love this tunnel. "You're beautiful, you're so beautiful, a little ugly, but beautiful" - and, in a nod to "The Princess Bride" - "As you wi-i-i-i-i-sh-h-h-h!" I didn't hear it myself, but the project's organizers reported that, at around 11:30 A.M. on that first Saturday, a marriage proposal was recorded: a man asked into the intercom, and the next recording, echoing down the line, was her response: "Yes." Lozano-Hemmer considered another art work made of light that has been drawing crowds this summer: James Turrell's exhibition at the Guggenheim Museum. Turrell is a genius at materializing light and making it "spiritual," Lozano-Hemmer said, whereas he is interested in light as "an artificiality: it's a party or an interrogation." For all his earnest intention, Lozano-Hemmer recognized "Voice Tunnel" as an opportunity to allow people to enjoy an unusual space for a finite period of time. For this one, we decided to go with party. Photograph by Spencer Platt/Getty.