There has been a lot of discussion about the acoustics of the Main Auditorium. In the beginning, there were problems, mainly because Aalto wanted the space to be like a medieval church in which the acoustics are known to be good. The tower section shown here was fully open. In the reparations that took place later, the ceiling was lowered to its present height, and the height of the stage was increased by half a metre. The doors of the Main Auditorium are covered with material made of horsehair. The organ in the Auditorium, made by the Kangasala Organ Factory, was the first concert hall organ in Finland. The front section of the organ was also designed by Alvar Aalto.