In a cellar, with paint peeling from the walls, a beautiful young man sits motionless at a desk whilst an old woman watches from the back of the room. Four black-clad musicians enter. After tuning-up, they strike the first chord of a Requiem. Tears well up in the motionless man's eyes and begin to snake their way down his chalk-white cheeks. This is the opening image of an astonishing performance created by Zofia Kalinska in homage to the great master of the Polish avant-garde, Tadeusz Kantor.

As the music swells, two figures – with hair as white as their powdered faces – emerge from the detritus of the cellar. Wrapped in bandages, their wise faces lined with age, they provide a striking counterpoint to the motionless young man who silently weeps. They bustle around him, muttering darkly, as the string quartet plays. Suddenly, a hollow-eyed figure appears at the window clawing at the pane. Death has arrived.

This description of Zofia Kalinska's Little Requiem for Kantor provides only an insubstantial stage direction for a visionary performance which transcends language and communicates on a purely emotional level. Call it spiritual or ritualistic if you like, this is theatre which resonates directly with the subconscious. The staggering beauty of Bartek Chajdecki's music and the intensity and focus of the performers (Zofia Kalinska, Mira Rychliska, Rebecca Brown, Sandy Grierson and Dera Cooper) create an atmosphere which is powerfully transfigurative.

I emerged from the cellar after this performance choked with emotion. I had witnessed, it felt like for the first time, theatre's potential to transform reality – to present, in poetic form, a mood or emotion which cannot be explained in words. I'm not sure that theatre can get any better than this.