Instead of the daily literacy and numeracy hours, the focus was Rousseau's picture Tiger in a Tropical Storm - Surprised, the National Gallery's colourful, almost cartoon depiction of a tiger standing, shocked, amid the dense foliage and the rain.
"We didn't want to be an exam factory for SATs results," says Mr Tyas. "We wanted a curriculum that was broad and balanced. We wanted arts and sport to be important to the children here."
The school's arts co-ordinator, Sarah Blair, planned the week to allow mixed-age classes and brought in artists and actors, musicians and dancers for a jungle-themed programme.They included a drumming group called Drumlove, who have since become regular visitors to the school. Before Drumlove, there were no children at St George's playing instruments: now there are eight drummers.
"You name it we did it," explains Sarah. "There were a lot of very busy children."
Where possible the artists were local. The sixth form college provided a student-led drama workshop and a local artist worked with children to produce drawings and pottery.
That was in 2001. The following year had circles as the arts week theme and this summer it will be the circus that dominates the children's thoughts.
Sarah Blair is already deep into the planning.
There have been many advantages on all sorts of levels, says Mr Tyas. In a big school of 540 children, for example, the project is a rare chance to get all the pupils and all the staff working together. The arts week also offers a valuable sense of continuity over the long summer break. When the children return in September the first thing they see is their own inspiring art work on the walls.
The Rousseau masterpiece, incidentally, shows the powers of the artistic imagination in even the least promising of circumstances. The painter himself claimed he had experienced the jungle while serving as a regimental bandsman in Mexico in the 1860s. But according to the National Gallery this was a fiction. Instead he almost certainly relied on visits to the botanical gardens in Paris, and other people's prints.