The modern dancer and choreographer Merce Cunningham died in 2009, and the company he led gave its final performance at the end of last year. Many of his dances will live on in the memories of former company members who go on to restage them. But there's one solo, "Loops," that Cunningham never taught to another dancer. This piece lives on through a different medium: digital motion capture.
"Loops," which Cunningham choreographed for himself in 1971, explores rotations of all kinds. Originally a full-body dance, "Loops" eventually narrowed to Cunningham's hands alone. In old age, Cunningham performed the piece seated in a chair. Now no living performer knows how to dance "Loops." But computer programs do, and they continue to create variations of Cunningham's work.
In August 2000, OpenEndedGroup, a trio of digital artists in New York City, affixed reflective markers to Cunningham's hands and had him perform "Loops" in front of infrared cameras, which recorded the markers' positions over time as a set of data points. This technique for digitalizing movement is called motion capture. It is employed in digitally animated films such as The Adventures of Tintin and in certain interactive videogaming systems — Kinect for Xbox 360 is an infrared camera that tracks the player's skeleton. In the dance world, motion capture is known as the technology behind BIPED, a 1999 collaboration between Cunningham and OpenEndedGroup, in which live dancers interacted with digital forms created using motion capture and projected on a transparent fabric. This time, motion capture recorded Cunningham himself.
OpenEndedGroup wrote software that interpreted the data from Cunningham's performance, and the digital representation of the dance differed significantly from the live performance. As OpenEndedGroup's Paul Kaiser described it: "We'd have a cat's cradle as well as hands. We'd have all these relationships that were going beyond human anatomy." The program made on-the-spot decisions about how to connect the motion capture dots. Altogether, OpenEndedGroup created four versions of "Loops"—tweaking the software every time.
But "Loops" lives on in perpetuity because OpenEndedGroup made the motion capture data open source. Any artist could download and reinterpret it. At the Boston Cyberarts Festival in 2009, four digital artists did just that —writing software that reinterpreted the raw motion capture data. The resulting works were displayed on computer screens at the Massachusetts Institute of Technology Museum in Cambridge in an exhibit called "Loops: New Iterations." The exhibit took place a few weeks before Cunningham died. "The piece became more poignant after his death," festival artist Golan Levin commented, "because suddenly it was like giving him a body that he had lost, in a way." Levin, a digital artist from Carnegie Mellon University in Pittsburgh, used the motion capture data to animate a pale globular structure that looks like a little man kicking and wiggling to get out of a white sac.
And so Cunningham's work continues to evolve through the technology he championed. Anyone could reinterpret the work today. But reinterpretation comes with criticism.
If OpenEndedGroup's Kaiser had his way, no one would mess with the "Loops" data. "After our experience with Cyberarts, we have no interest in anyone else interpreting it, since it was so stupid," he said. "None of [the four artists] engaged anything of interest, certainly not with the motions of Cunningham," Kaiser said.
In his iteration for the Cyberarts Festival, Brian Knep, the artist in residence at Harvard Medical School, chose not to engage with Cunningham's dance movements. "When I first downloaded and started playing with the captured data," Knep said, "I kept coming back to the reference footage, captivated by watching Merce's facial expressions. This had far more meaning to me than any of the data." For his interpretation, Knep took the original video footage of Cunningham's performance, then zoomed in on Cunningham's face, completely cutting out the hands. Two numbers at the bottom of the screen, the speeds of Cunningham's hidden hands, are the only representation of the motion capture data.
No one will ever know what Cunningham thought of his new avatars, but Kaiser clearly takes offense: "I found the whole thing insulting, if not to us, certainly to Merce."
Abby Diaz, a graduate student studying digital media at New York University, is not surprised by Kaiser's disappointment. "I think it's a little naïve to think that when you open source code, people are going to make masterpieces out of it."
Though people may disagree about the form they take, Merce Cunningham's motions will endure as long as there are computers and Internet connections. "Loops" has transcended the medium of the dancer. It has a life of its own.
This article is provided by Scienceline, a project of New York University's Science, Health and Environmental Reporting Program.