Klee was the master of line as well as colour

But Klee's reputation has fluctuated with the fortunes of these painters, and has never been as high in Europe as in the United States.

The new show demonstrates that Klee was the master of the line as well as colour, and that his simultaneous exploration of the world of rhythm, perspective and representation was reflected in his work.

Klee argued that it was not the role of the true artist to reproduce reality, but rather find a deeper, inner reality which had been invisible.

He had a chance to put his theories to the test as a faculty member of the Bauhaus - the influential art school that was the hothouse of inter-war modernism.

Unusually articulate, Klee spelled out his theories in articles, notebooks and diaries, some of which are reproduced in a slide-show.

Like his contemporary Wassily Kandinsky, he was concerned to expand the vocabulary of painting, using line, colour, and texture in powerful juxtapositions.

His paintings have a magical quality, turning the ordinary into the profound - for example in his whimsical painting, The Distillation of Pears.

The show was curated by British artist Bridget Riley

The show is full of surprises, including the series of paintings that Klee made reflecting his musical sense, full of small lines that combine in a colour field to produce a forest or a castle.

It also points out that his most well-known paintings - bold lines across coloured squares - were a product of a disabling illness late in his life. Like Matisse's famous paper cut-outs, produced after the artist became blind, Klee managed to transform his disability into a more profound art.

If the show has a weakness, it is that it does not show enough of Klee's later work, and especially his use of other materials (shown as his painting on wood tablets).

The show was curated by British artist Bridget Riley, who supplies a moving introduction in the catalogue that could well have been incorporated in the show.

But like all good exhibitions, it opens the way for the artist in the spotlight to be re-interpreted for the next generation.

The Paul Klee exhibition is at the Hayward Gallery in London's South Bank Arts Complex until 1 April