Cochereau was allowed the key to the local church so he could practise piano, however one day he discovered a 2 manual pipe organ by Cavaillé-Coll.
He continued his organ studies with André Fleury and Paul Delafosse, whom Cochereau succeeded as titular organist at Saint-Roch in Paris in 1942.
One year later, he married Nicole Lacroix, a pianist and composer, with whom he had two children: Jean-Marc (1949–2011), conductor and late director of the Tours Conservatory, and Marie-Pierre, a professional harpist.
In 1955, he succeeded Léonce de Saint-Martin (1886–1954) as titular organist at Notre Dame Cathedral in Paris,[1] after applying to the post just days before the deadline.
Pierre Cochereau died in the early hours of 6 March 1984 in Lyon[2] after suffering from a cerebral hemorrhage; he unsuccessfully attempted to reach a telephone to call for help.
Following his death, Notre-Dame appointed four titulaires des grands orgues: Olivier Latry, Yves Devernay (died 1990), Philippe Lefèbvre and Jean-Pierre Leguay (retired 2015).
His many stylistic influences regarding counterpoint, formal structure, and harmonic language included composers such as Marcel Dupré, Maurice Duruflé, Noël Gallon, Olivier Messiaen, and Florent Schmitt.
Many of Cochereau's organ improvisations have been transcribed and published by other organists, such as David Briggs, Jeremy Filsell and Jeanne Joulain.