What are two pairs of faded Levi's with white Calvin Klein underwear inside - rumpled and tossed on the floor - doing in show in a museum of contemporary art? And above all why is "the work of art" - created in 1998 by the Danish couple, Michael Elmgreen & Dragset Ingarda and entitled Powerless Structures - repeated again in the second section of the show? It is one of the many questions that the public will ask when visiting "Exhibition, Exhibition" (until Jan. 9, 2011, for information: www.castellodirivoli.org), the show that the staff opened for the fall-winter season at Castello di Rivoli. And they do it by adopting an unusual and interesting, albeit perhaps a bit convoluted, mix of approaches, styles and languages from painting and video to photography and sculpture to ready-made and performance (the two dancers, a man and a woman, engaged in ritual choreography by Tino Sehgal). Adam Carr, the young and very British curator, is responsible for setting that silent presence of art and more in general, of Western culture - the double - in the former Savoy residence. Starting from the enigmatic title, "Exhibition, Exhibition" with the repeated word separated by a comma.

Andrea Bellini, the museum's newly appointed co-director (along with Beatrice Merz: here, again duplicity returns ...), says, "It is a special and site-specific project conceived for the Castello's long wing. With a corridor that is 147 meters long and just 6 meter wide - the exact opposite of the classic and neutral white cube - the idea is to transform spatial constraints into added value by commissioning a series of installations designed specifically for the space. Next year, for example, I would like to invite Daniel Buren."

Carr accepted the challenge and raised the ante. First he divided the space into two sections, each with different rooms reflecting each another, thus visualizing the concept of duplication even from an architectural standpoint. And then he puts together some forty artists; each different in terms of poetics, geography and generation - from the late Andy Warhol to the 25 year-old Lithuanian Gintaras Didziapetris – and each presenting a pair of pieces. Thus, the protagonists of the different historical avant-gardes of the last half a century coexist with emerging artists. Conceptual (the Cuban Wilfredo Prieto) and arte povera (Michelangelo Pistoletto) stand side by side with the new that is advancing (Lara Favaretto and her lost luggage in Lost & Foun; the young Alek O. using objects from her own memory like old corkscrews merged into small minimalist sculptures). The pieces interweave in a play of mirrors, between "double vision" and déjà vu, not without some shifts in meaning.

In this sense, the first room is emblematic; here, Giulio Paolini's first conceptual piece (Disegno geometrico, 1960) meets Gemelli by Alighiero Boetti (two seemingly identical portraits from 1968 brought together in a photomontage in which the artist holds hands with an image of himself that is the same but different) and Essere fiume 6 by Giuseppe Penone, a piece dating from 1998 that consists in two large stones that seem the same, but in reality one was taken from a mountain stream and the other was carved based on the model.

If, for Penone, art "copies" nature, for Maurizio Cattelan art "copies" art and doubles it (going a step beyond Oscar Wilde's famous quote that life copies art and not vice versa). In 1997, the artist - famous for his provocations - chose to reproduce the entire Carsten Höller show at the Art de Paris Gallery and exhibit it in Emmanuel Perrotin's adjacent space; even the press release and prices were identical. Moi-Même, Soi-Même is an artefact of copyright theft, a portrait of Carsten Höller from behind (of course in the Rivoli show, the original by the robbed artist is also on view). "For this reason we have also included two emblematic pieces by Warhol, Marilyn (1967) and Flowers (1971);" said Carr, " he was a pioneer in bringing into play the concept of authenticity and the unique piece, working on the double, on the series and on repetition." Warhol's lesson, taken up by 40 year-old Jonathan Monk who replicates, in two nearly identical pieces, the famous A Bigger Splash by British master David Hockney. Except for the titles, Before a Bigger Splash and After a Bigger Splash, there is no trace of the dive in the paintings. "Exhibition, Exhibition" concludes with yet another dizzying mirror effect. In fact, the last piece recalls the first one and is again signed by Giulio Paolini. In Dopo tutto, created for the long wing and completed on September 19, 2010, the day before the show's opening, is a portrait of the painter who, with the same perspective as the viewer, sees his own drawing "explode" into fragments of a puzzle. It is as though the art object's real double - and that of our visual perception - were the very space in which it is exhibited.