The 2009 TIME 100

Elizabeth Diller, 54, and Ricardo Scofidio, 74, once described architecture as slow and cumbersome. Their work is anything but. The husband-and-wife team's creative fearlessness results in design that defies categorization. The emergence of Diller Scofidio + Renfro (Charles Renfro was added as a name partner in 2004) on the global stage of built projects is something to be celebrated.

At the Institute of Contemporary Art in Boston, the architects floated the galleries in the sky, creating a public space beneath that embraces the waterfront. For the High Line in New York City, the first phase of which opens in June, they invented a paving system to repurpose elevated train tracks into a public park, colonizing forgotten crevices of Manhattan.

Not long ago, I talked with Ric and Liz about their approach to the revitalization of Lincoln Center's Alice Tully Hall. The conversation segued from origami to car-racing to striptease and ultimately to the building. They move between worlds with an exhilarating intellectual stealth — which is probably one of the reasons they were the first architects to win a MacArthur Foundation award, in 1999.

At Alice Tully, the architects sliced off a corner of the block to create a public space that lets performance out and invites the city in. It is generous and embracing. Just like Ric and Liz.

Rockwell is the founder and CEO of the Rockwell Group

Fast Fact: The duo's Blur Building was a cloud that hovered over a Swiss lake

See why Diller & Scofidio made the TIME 100 list