One day in Prague's Orloi Square, bystanders witnessed what many likely assumed was either a brown, velour-jacketed flash mob or massive staging of performance art. Those people would only be partly right.

The scene, which involved over 500 people, mounds of crushed ice and 15,000 free bottles of Coke, was actually the 'set' for a digital video reality spot, "Pour", from MacLaren McCann, Toronto - a fact that would become quickly evident when the same people were asked to sign release forms.

Shot primarily from a helicopter with 10 cameras on the ground, the spot, which is currently running in cinemas in Canada, Southeast Asia and Eastern Europe, begins with a hoard of people who spontaneously enter the public square, drop their backpacks, don their jackets and form the shape of a Coke bottle. The mass then pours from the bottle into a chalk outline of a glass.

Geometry played an integral part in both the choice of Prague as the location and the success of the human choreography. "Creatively, the script required a really large square or piazza that would allow a bottle that would hold 500 people in brown suits and a glass to accommodate them afterwards," notes Andy Manson, VP, executive group creative director at MacLaren McCann. "Plus it had to have room for people to mill around on the outside."

There were a few other possibilities such as Argentina and Brazil, but between the economics of such a large cast and the need to be able to hover a chopper over the center of the city at just over 1,000 feet, Prague was the clear choice.

"The municipality is quite flexible with permissions as long as we play by the rules," says Fady Salameh, executive producer of local production company, Dawson Films. "They have some restrictions regarding how many times a month we can shoot there or not. We were lucky that we fit with the parameters."

Dawson's responsibility covered everything in front of the camera, such as finding masses of crushed ice, which they got from a local company that facilitates large parties, and securing a helicopter. Local gear such as a Tyler mount was sourced by AD Artist Robinson.

To man the chopper, Salameh used a local pilot familiar with city flying for hospitals - and rescue missions. His skills were tested on shoot day. Director Steve Chase, of Toronto's Partners Film Company, probably didn't storyboard himself hanging out an open door high above the square in the howling wind, but that's exactly where he found himself for the master shot after vibrations made the images from a helicopter-mounted camera useless.

"I put my seatbelt on with a rope around my waist and tied it to the pilot's seat because I figured if I'm going, he's going too," recalls Chase.

Despite drift which made it virtually impossible to line up the frame, they managed 15 complete takes. For the set-ups at ground level, 10 DV cameras were spread out across the square to capture various elements, including authentic reactions from passersby in the square, who were entertained by buskers beforehand to keep them there long enough for the pour.

"It was a little challenging," remembers agency producer, Franca Piacente. "We had a lot of PAs and we would be running after people to get them to sign releases. There were a lot of people we weren't able to get, so we couldn't use them in the edit."

To determine the magic number of people needed to adequately fill the colossal bottle and glass, Chase projected the shape of the iconic bottle onto a wall in a warehouse. Once the right size was found, carpet was mounted on the wall, cut in the shapes of the bottle and glass and laid down in the parking lot a day before the shoot so the extras could practice on it.

Following a day lost to weather, and apart from Chase's aerial heroics, the main shoot day went according to plan. The extras hit their marks like old pros and the production had hours of footage to cut into a :60. Neither Chase nor MacLaren had shot in Prague, but they were captivated by both the local craftsmanship and the city itself.

"It's like a museum, but where you can have all the fun," says native Salameh. "It's a colorful city. We know how lucky we are."

MacLaren McCann> www.maclaren.com
Partners Film Company> www.partnersfilm.com