Visitors who enter the darkness of the Hangar Bicocca (which reopens to the public renovated and with new spaces e.g. bistro, bookshop, foyer and garden) come face to face with Kiefer's high towers. They have to wait a little longer for the work by Boltanski, the artist who will represent France at the 2011 Venice Biennale. First they have to follow an interesting straight route lit only by neon bulbs, accompanied by the rhythmic and rising sound of thousands of hearts beating. A brightly-lit room at the end of the corridor is filled with a huge mountain of coloured garments. Piled on top of each other, they are grabbed and moved at random by a small crane suspended from the ceiling. This is Personnes, the installation presented last January at the Grand Palais in Paris during "Monumenta" but totally rethought for the Hangar Bicocca in Milan.

The same installation set in three very different places. What are the main differences between the architecture of the Grand Palais, the Armory and the Hangar Bicocca?
Working in the Grand Palais was the hardest because it is very baroque architecture. The Armory, a 19th-century industrial space, and the Hangar were easier because they are more modern spaces, spaces of today. Personnes is always the same work but a different one, at the same time. I see it as being like a music score that I play differently each time. You start again in each place with new elements. You could say that in Paris it was like playing with a large orchestra; here, with a chamber orchestra. I can imagine someone else performing this work in 30 years' time, when I am no longer around, and they will do it slightly differently each time.

How important is the relationship with the space?
I believe all artists ought to think about the relationship with the space and the relationship with what is in that space. We are not standing in front of a work but inside it. When we walk down the corridor, with the sound gradually getting louder, we cannot see anything; we are advancing alone towards death. Even the spectators, observed by those outside, become parts of the artwork.

What is the relationship between the long walk leading to the installation and Anselm Kiefer's I Sette Palazzi Celesti standing alongside it?
The dialogue with Kiefer's work, which I find very beautiful, was one of the strong points and the challenges of this place, partly because his work is very different from mine. We both talk about the same subject, death, but not from the same standpoint.

What is the meaning of Personnes?
I see Personnes as a tragic work but it is also very colourful; it could almost be an Impressionist painting. It could be interpreted as an almost joyous work. It is built on the idea of chance, of luck. Every garment represents a person. There are 30 years of clothes here – there could be 500,000 people. The crane is like the hand of God that blindly takes people at random. As you grow older you gradually start to wonder why one person dies instead of another, or you yourself. You begin to think there are no real reasons why one lives and another dies. And, of course, there are no answers. Personnes is a work on the randomness of death.

Why clothes?
I see a garment as the equivalent of a body. It is like a photograph of someone, their heartbeat. It is an object that reminds you of a subject who is not there and highlights their absence. My work revolves around the individual and the group. The real issue in my work is the importance of each individual, this great mass of people and their disappearance.

Since 2008 and the "Les Archives du Coeur" project, you have been collecting people's heartbeats. Is the project continuing in Milan?
In Milan too, as in Paris, there will be a booth recording the visitors' heartbeats. You pay a few Euros and receive a CD in return. The beats will be sent to Teshima, an island in southern Japan, where the archives financed by a foundation will open on 18 July. It already contains 30,000 heartbeats and that number will rise. Within 20 years, many of those hearts will belong to dead people. So the island will become an island of the dead.

Why in Japan?
Because it is the idea of the journey that interests me. It is a bit like a pilgrimage. The important thing is that, if you want to listen to your mother's heartbeat, you have to make this journey and think about her. It becomes a reflection on her absence. We try to conserve life but, of course, this is not possible. You can conserve someone's heartbeat, but not the person themselves. What I want to do is explore a subject, such as death, that is taboo in today's society. There is a rejection of getting old and dying. I have also created a permanent work this year, a speaking clock on Strasbourg cathedral. You descend into a crypt where a computer announces the time day and night, every second. It cannot be stopped. Here, the image of God is that of the lord of time. We can do many things but not fight passing time.

Video, sound and installation are some of the media you use in your works. Yet, I have read that you like to call yourself a sculptor, even though actually you have not sculpted for many years.
I think there are two types of art: the art of time (works that have a beginning and an end, like films and literature) and the art of space. I consider myself a sculptor, an artist who works in space. And I believe I am very traditional because I pose very traditional questions, which could have been asked by an artist of the Renaissance or the Middle Ages. Science makes progress but art does not. I am convinced there are very few subjects: sex, the search for God, nature… Five or six in all. Everyone expresses themselves with the words of their times, which today are sound, video, photography. But we all say the same thing.

The clothes were recycled at the end of the Paris exhibition. What will happen in Milan?
The clothes will be collected in lots of bags marked "Boltanski Dispersion". People can come here and take them home. It will be a sort of resurrection; things that belonged to someone who is dead or no longer used them will set off on a new life. Everyone can do what they like; some will conserve them like a work of art and others will use them to go shopping.

So, there is a message of hope in this work...
Yes, and it is important for each person to interpret this work as they wish - tragically but also joyfully. It is an open work of art and it is always the onlooker who determines its meaning. It is a slightly Minimalist work. People are always telling me I am a sentimental Minimalist artist. It is a contradiction but I think it is a good definition. My vocabulary is bound to Minimalism, partly because of my generation. But, I am also quite sentimental.