The church contains a large four-manual pipe organ built in 1890 by Aristide Cavaillé-Coll. This instrument is considered to be one of the most important organs in France, and is notable for its unusually powerful 32' Contre Bombarde. The organ stands unaltered and thus is one of the few of the master's works to speak with its original voice.
The pipe organ is a big box of whistles. Each pipe sits on top of a hollow wind chest that is filled with compressed air provided by a bellows or blower. Each ‘stop’ at the organ console represents a set of pipes (a rank) of a particular tone color, with a different pipe for every note on the keyboard. Pulling the stop activates a slider under that specific set of pipes on the windchest, making them available as a sound-source. The wind chest also contains a series of valves (pal