From 1921 to 1991, the Busch–Reisinger was located in Adolphus Busch Hall at 29 Kirkland Street. The Hall continues to house the Busch–Reisinger's founding collection of medieval plaster casts and an exhibition on the history of the Busch–Reisinger Museum; it also hosts concerts on its Flentrop pipe organ. In 1991, the Busch–Reisinger moved to the new Werner Otto Hall, designed by Gwathmey Siegel & Associates, at 32 Quincy Street.[1]