The church organ is located in the apse of the main altar.
Together with the meticulously inlaid wooden choir, it creates a spectacular scenic backdrop. It is a monumental instrument, a great scenographic machine created by the artist Donato del Piano, who worked on it for 12 years and changed the design several times at the request of the Benedictine monks.
The complicated organ has 2378 wooden and tin alloy pipes, six bellows, seventy-two stops and five keyboards. It was able to reproduce the sound of any musical instrument.