The church’s Gothic Revival architecture is among the most dramatic in the world; its interior is grand and colourful, its ceiling is coloured deep blue and decorated with golden stars, and the rest of the sanctuary is a polychrome of blues, azures, reds, purples, silver, and gold. It is filled with hundreds of intricate wooden carvings and several religious statues. Unusual for a church, the stained glass windows along the walls of the sanctuary do not depict biblical scenes, but rather scenes from the religious history of Montreal. It also has a Casavant Frères pipe organ, dated 1891, which comprises four keyboards, 92 stops using electropneumatic action and an adjustable combination system, 7000 individual pipes and a pedal board.
Orchestras, chamber groups and organists appear regularly at Notre-Dame Basilica. Music lovers and concertgoers have the opportunity to hear a wide variety of unique performances, in a remarkable acoustical space whose physical beauty adds to the magic of the moment.