By the 1960s, these show places felt the competition from television and other factors which adversely affected first-run theatres nationally. Because of its superior acoustics, the St. Louis Theatre was acquired by the Symphony Society and, for at a cost of $5,000,000, converted into the society´s first home of its own. The second oldest of the nation´s symphony orchestras, the St. Louis Orchestra had performed in Kiel Opera House, with competition from sports events in the adjacent convention hall.

Clark Graves was engaged as interior designer for the project, which was named for Walker S. Powell, whose widow contributed $1 million towards the cost. While many of the baroque decorations were retained, major physical changes included a reduction of the seating capacity to 2,700.

Restoration of the interior included replacing the lobby´s worn terrazzo with marble, rehanging Italian Crystal chandeliers, covering the stairs and halls with red carpet, and painting the walls and ceilings cream white. So much gold leaf was required to gild the plaster decoration that the American supply was entirely exhausted and more had to be flown in from Germany.

The concrete auditorium floor was covered with a double layer of wood for resonance, the eight-story stage lowered to a five-story permanent shell, and walls and doors sound proofed. It is estaimated that the symphony saved at least $10 million by adapting the structure rather than building a new one.

Since the Powell Hall conversion, movie theatres in Pittsburgh (Pantages Movie Theatre), Oakland, CA (Paramount Theatre) and Youngstown, OH have also been converted as symphony halls.