Mulet served for a time as organist of The Basilica of Sacré-Cœur.
His most well-known work is Les Esquisses byzantines (Byzantine Sketches) in which each movement extolls an aspect of Sacré-Cœur, supposedly Byzantine in its distinct architecture.
The tenth and last movement, most often played, is a toccata entitled: "Tu es petra et portæ inferi non prævalebunt adversus te (You are the rock and the gates of hell shall not prevail against you).”
In Matthew's gospel (16:18), Jesus says to Peter:“Tu es Petrus and super hanc petram aedificabo ecclesiam mean et portae inferi non praevalebunt adversum eam.” “You are Peter and on this rock I shall build my Church and the gates of hell shall not prevail against it.”
Mulet rewrites the Latin and makes Sacré-Cœur the rock that will withstand the gates of hell.
A rock in the Hebrew scripture and even in medieval Europe often means fortress, a point of repair, of defence. "The Lord is my rock (2 Samuel 22:2)."
To listen to Tu es petra, performed by Gillian Weir on the 1974 Phelps organ of Hexham Abbey, England, click here, then click on "Part II," then hold button and slide to 25:47 (25 minutes and 47 seconds).
To listen to Tu es petra, performed by Donald Livingston on 1927 Casavant / 2001 Schantz organ of St. Andrew's Lutheran Church in Mahtomedi, MN, click here, then click on "Listen to the Program," then hold button and slide to 1:19:12 (1 hour and 19 minutes and 12 seconds).