Aristide Cavaillé-Coll was a French organ builder. He has the reputation of being the most distinguished organ builder of the 19th century. He pioneered innovations in the art and science of organ building that permeated the profession and influenced the course of organ building, composing and improvising through the early 20th century.

The Basilica of Saint-Denis is a large former medieval abbey church and present cathedral in the commune of Saint-Denis, a northern suburb of Paris. The building is of singular importance historically and architecturally as its choir, completed in 1144, is widely considered the first structure to employ all of the elements of Gothic architecture.