Coventry's Belgrade Theatre has closed until the end of the year for major redevelopment work.
The £12 million scheme has already started. A seven-storey extension is under way on Bond Street, which will house a second auditorium which is due to open early in 2007.
Sunday's production was the last in the main house until the end of the year.
Project director David Beidas said: "Six months after works started on site, the new building can finally be seen emerging above the hoardings."
He added: "Work is well under way on constructing the concrete core structure of the new extension which will house the new auditorium and rehearsal room."
The plan includes a seven-storey extension with up to 300 seats and flexible staging in a second auditorium.
There will be a glazed main entrance from Bond Street, a rehearsal facility and a terrace. The existing listed 1950s building will be refurbished to include new ventilation for the 850-seat main house.
The venue takes its name from the city of Belgrade, whose residents gave money to Coventry after the Second World War.