Banff Centre iCORE researcher Chris Chafe explores the intersection between time, distance, and music

From a Banff studio, musicians perform with colleagues around the world.

Chris Chafe spent the past year chasing milliseconds.

A composer, musician, and scientist, Chafe has devoted much of his professional life to exploring musical performance over networks. Recent advances in audio and Internet technology have enabled the delivery of live high-quality sound to far-flung locations, but the time delay inherent in network transmission remains a significant stumbling block.

“In a telephone conversation, a 150-millisecond delay is the norm,” says Chafe. “In fact, a telephone conversation can tolerate up to a half-second delay. But that doesn’t work for music. Music is about simultaneity. Research shows that a 20- to 25- millisecond delay is the upper limit for ensemble playing. Anything more disrupts the subtle shadings of rhythm and emphasis that generate musical expression.”

Chafe spent the past year as a Banff Centre iCORE Visiting Professor. On sabbatical from his role as director of the Stanford University Center for Computer Research in Music and Acoustics (CCRMA), Chafe worked with the Centre’s Audio department to research new technologies that will enable musicians in distant locations to rehearse and perform together seamlessly.

The benefits are many, Chafe explains. “It brings musicians together, regardless of where they live. So it creates new possibilities for collaboration across distance and international borders. Potentially I could be a drummer sitting in my bedroom in Berkeley jamming with a bass player in Japan.”

And, he adds, it’s green. “Less travel equals less carbon footprint.” Chafe notes that there is already a five-member band in the Bay area rehearsing over the Net, coming together only at live gigs.

Much of Chafe’s work focuses on eliminating, or finding ways to compensate for, the delay caused by network transmission. “We’ve gotten to the point where we are playing with very small increments of time, but the effects remain real.” Adding to the conundrum, Chafe notes, is the fact that the delay increases with the network distance.

“In a face-to-face situation,” he explains, “sound travels at one foot per millisecond. Musicians are used to compensating for that. That’s why string quartets sit so close together — to minimize the delay.”

“But, when we link Banff with Ireland we get a 100-millisecond network delay – the equivalent to seating the players 100 feet apart — and it becomes very difficult to play synchronously.”

While previous research focused on using high-quality telecommunications lines to link musicians, Chafe’s current work revolves around Internet transmission. “What’s great about the web is that it is open source and open access,” says Chafe. “The potential exists to find a solution everyone would have access to.”

Over the course of his iCORE year, Chafe worked in Banff to develop improved software for audio over Internet transmission, publish his findings, and research the role video cues play in networked performance.

“In real life visual cues arrive before audio cues. Light travels faster than sound. You see the conductor move before you hear the downbeat. The opposite is true in network situations. Video transmission takes longer than audio transmission.”

The Banff Centre is the ideal location for such research says Chafe. “You have world-class musicians, an audio engineering program unique in North America, and access to an advanced high-capacity network.”

Theresa Leonard, the Centre’s director of Audio, says Chafe’s research opens many possibilities. “It has the potential to eliminate the barriers caused by distance, to unite teachers and students, and to uncover talent that might be missed.”

During the 2009 Banff Centre jazz program, Chafe organized three Telejazz networked performances. “In the first case, involving musicians in Banff and Calgary, the network delay was minimal and it worked fine,” he says. “When we hooked Banff up to players at Humber College in Toronto, the delay – about 30 milliseconds —was significant and the rehearsal was a bit hairy. But for the live performance, the musicians rose to the occasion and overcame it. The last Telejazz performance, linking performers in San Diego, New York, and Ireland, was a bit slushy due to the longer delay, so we adapted the music to pieces less dependent on timing.”

In November, Chafe’s creative chops and his audio research came together for a five-location networked performance called ResoNations: An International Telematic Music Concert for Peace. Linking musicians in Banff, New York, San Diego, Belfast, and Seoul, the performance featured Chafe’s Rock, Paper, Scissors, a work composed specifically for networked performers.

“Five years ago I wouldn’t have imagined we would have this capability,” says Chafe. “I’ve been surprised by the speed of progress. And best of all, it’s free — or at least very cheap. All you need is a computer, access to the Internet, and the will to perform.”

“We’re inventing a new sound space for interaction — a world-wide concert hall.”

iCORE – the Alberta Informatics Circle of Research Excellence was established in October 1999 by the Government of Alberta to foster researchers in the field of informatics.