Roy Thomson Hall is a concert hall in Toronto, Ontario, Canada. Located downtown in the city's entertainment district, it is home to the Toronto Symphony Orchestra and Toronto Mendelssohn Choir. Opened in 1982, its circular architectural design exhibits a sloping and curvilinear glass exterior. It was designed by Canadian architects Arthur Erickson and Mathers and Haldenby. The hall seats 2,630 guests and features a pipe organ built by Canadian organ builders Gabriel Kney of London, Ontario.