Glasgow: Britain's Turner Prize has long stirred debate in the art world with its unconventional choices, and this year may be no different with a song performance and an architecture collective among the contenders.

An exhibition of the four finalists' work begins in a room of modern chairs with fur coats sewn onto them, by London-based German artist Nicole Wermers.

On the wall are ceramic sculptures resembling advertisements with numbers that can be torn off.

"Both projects are about crystallising fleeting social gestures -- the placing of a coat on a chair to mark space, the tearing of a number off the wall to get information -- into rigid sculptural form," said co-curator Paul Pieroni.

"This is the most conventional part of the exhibition, it's sculptural objects in the traditional sense."

Stepping into the next section of the exhibition -- which opens Thursday at the Tramway arts centre in Glasgow -- visitors' feet sink into thick carpet, a contrast to the rough concrete floor of the rest of the gallery.

They have entered the supernatural study centre of British artist Bonnie Camplin.

The room contains five televisions with headphones, where visitors can listen to people explaining supernatural events they claim to have experienced.

Around the room are books and scientific articles, aiming to help visitors assess whether the tales are true.

"The project as a whole is really about questioning what it is we take to be consensus reality. So it's pushing the limit of what we might say is real or unreal, believable or unbelievable," Pieroni said.

- 'Alarm, danger and violence' -

The third component of the exhibition features the enigmatic work of 45-year-old Canadian artist Janice Kerbel.

The musical composition, "DOUG", is performed by six opera singers dressed in black who sing songs recounting a series of disasters that happened to a person named Doug.

"You can really feel the alarm, the danger and the violence. It's making something physically manifest through spoken words alone," said co-curator Claire Jackson.

The work will be performed every day of the exhibition, which will be open until 17 January, sometimes partially and sometimes in its entirety.

The final part of the show explores the work of Assemble, a group of 18 young people working in architecture and design who are one of the Turner Prize's most unexpected candidates in recent years.

The work that drew the nomination was the group's refurbishing of Victorian homes in Toxteth, a district of Liverpool that had fallen into disrepair and dereliction after riots in 1981, where residents have long battled against demolition.

The ongoing project works with the idiosyncracies of the properties, making double-height rooms where ceilings have fallen in, and creating a "winter garden" inside a pair of houses that are no longer habitable.

As the houses themselves cannot go on show, the exhibition is dedicated to their Liverpool workshop, in which they worked with local young people to build items such as fireplace surrounds, door handles and stools for the project.

"They are offering a really interesting new dialogue around how architecture, visual arts, design and craft interact," said Jackson.

"This idea that there is one role for the artist is becoming increasingly blurred."

The contemporary art prize, which is named after painter William Turner, has been awarded annually since 1984 to an artist aged under 50 who is living in, or was born in, Britain.

Among its past winners was Damien Hirst, for his bisected cow and calf preserved in formaldehyde.