One of the jewels of the National Gallery is a room. The Rideau Chapel adjoins the garden courtyard. The Convent of Our Lady of the Sacred Heart dated to 1887-88, and was torn down in the 1970s. The chapel was preserved and installed here. Its Tudor style fan vaulted ceiling is unique in North America, and the altar is from the chapel. Religious statues adorn the room, saints and angels. Most of the time when I visit, speakers are set up around the room. The Forty Part Motet is a sound sculpture by Janet Cardiff, with singers performing a reworked version of a 16th century composition by the English composer Thomas Tallis. One can stand near one speaker and hear the voice of a single singer distinctly, or stand in the middle of the room and feel wrapped up in the work as a whole.
Check out here for a video about the Gallery's chapel and the music, and here for a video commentary by Janet Cardiff herself about the work, which has homes in other parts of the world as well as here. The Chapel is very peaceful, and the Motet feels entirely fitting for this space.