MILAN, ITALY — The world's oldest and most prestigious contemporary art fair opens Sunday in Venice, kicking off what promises to be the European art season of the decade as four premier events align in an unusual convergence that is generating buzz.

Following this weekend's opening of the 52nd Venice Biennale, Art Basel in Switzerland, Documenta in Kassel, Germany, and the Muenster Sculpture Project all kick off in quick succession, creating much excitement and hurried travel since only rarely do the major art-fair cycles coincide.

But while Documenta, opening Saturday, draws hipper crowds and Art Basel, Wednesday, attracts the buyers, it is the Venice Biennale that is "the most noble," one former curator said. The Biennale is also special because it's held every two years while its rivals are annual events.

In its 120-year history, the Biennale has advanced art discourse by presenting to the public such notables as Gustav Klimt, Pablo Picasso and the Pop Art movement. Recent editions have drawn several hundred thousand people to the lagoon exhibit spaces during five months — still just a fraction of Documenta's expected attendance, a consequence of Venice's expense and difficult geography.

Each edition of the nearly six-month Biennale is unique, reflecting the choices of the curator of the main international exhibition.

This year, the job has fallen to American curator and critic Robert Storr, currently the dean of the Yale School of Art and former painting and sculpture curator at the Museum of Modern Art in New York. He is among only a handful of non-Italians to be given the honor.

Storr's exhibition unites about 100 artists in what many observers who have seen the show in previews described as a more unified museum approach to the Biennale, known for its sometimes chaotic attempt to showcase fresh art, often by young, emerging artists. More