How much room do you need as a space for art? Not very much is the answer - to judge from the Loge, hidden behind two small Tudor-style windows in a fine old building dating back to the pre-Wall united Berlin. This is what Martin Mlecko and Wolfgang Schöddert must have said when they chose this old marble-lined porter's lodge as the location for their new gallery project, after twenty years of taking art to unusual spaces. But are four square metres really enough? Anyone walking down Friedrichstrasse just by Checkpoint Charlie on the evening of 28 October would have seen - and heard - that they are. Behind the Loge's tiny windows, an opera singer (Ruth Rosenfeld) in a long black gown was singing an aria to anyone who wanted to go inside - one at a time, a solo for a public of one, face to face with the artist in the tiny white space.

This was SOLO, a performance that was part of the Soundfair programme (run by Ari Benjamin Meyers and Clara Meister) which aims to turn the Loge into the world's smallest auditorium. Soundfair continues in December with another performance of SOLO. This will be followed in January by 11 auf 4; for this, a temporary structure will allow the Loge to accommodate an 11-piece chamber orchestra in black tie. How much space does a chamber orchestra need anyway? Vincenzo Latronico