Shortly before 10:30 a.m. (09:30 GMT), the bells rang out one by one, the smallest followed by the largest, powered by motors, until they formed a harmonious ballet, according to AFP journalists on the scene.
Five shocking minutes for those who witnessed them.
"We all felt an intense emotion, it is a voice that extends, that brings us closer. It is November 8 and Notre-Dame tells us 'I am here, I am waiting for you'," declared Father Guillaume Normand, vice-rector of the cathedral.
The eight bells, bearing the names of personalities who have marked the life of the diocese and the Church, rang out in full force - in full - and at full blast, "a sign of joy", the priest stressed.
They had not resounded in the Paris sky since April 15, 2019, the date of the fire that ravaged the cathedral, a masterpiece of Gothic art built more than 850 years ago.
"It's a beautiful, important, symbolic step," said Philippe Jost, head of the restoration of Notre-Dame de Paris. Because "all the bells together, it's the first time."
"Everything is not yet perfect. We will adjust it to perfection but this first test is conclusive," declared, moved, Alexandre Gougeon, from the Gougeon company, project manager for the replacement of the bells for the ATC group, hailing "a great achievement."
Individual bell-by-bell tests were conducted on Thursday after the engines were installed.
Guest artists
This sound signal marks a further step in the resurrection of one of the largest cathedrals in the West, a UNESCO World Heritage Site and one of the most visited monuments in Europe.
During the fire, the flames had reached part of the northern belfry of the building, which had to be restored. To do this, the eight bells of this tower were carefully removed, cleaned of lead dust and restored, most of them in Normandy (west), before returning to their original setting.
From "Gabriel", and its more than four tons, to the smallest "Jean-Marie" (around 800 kg), named in homage to Cardinal Jean-Marie Lustiger, Archbishop of Paris from 1981 to 2005, these eight bells returned to Notre-Dame in mid-September during a small ceremony and were blessed on the occasion.
A month before its reopening, Notre-Dame de Paris has regained its familiar silhouette and is preparing to receive its first visitors on December 7, before a mass the following day.
The project will have mobilized 250 companies, hundreds of craftsmen and cost nearly 700 million euros, financed by 846 million euros in donations.
The details of the December 7 ceremony remain unclear, but "there will be very good artists, very great artists of international renown, that's what the cathedral deserves," Philippe Jost said on RTL on Friday, lifting the veil on a well-kept secret.
Press reports have suggested that ex-Beatle Paul McCartney will be there, a possibility that has never been confirmed.
"Wonder"
The only certainty at this stage is that President Emmanuel Macron will speak "in the cathedral". "If we will be in front of the reopened Notre-Dame de Paris on December 7, it is because he launched this challenge of (reconstruction in) 5 years", Mr. Jost stressed.
Notre-Dame welcomed 12 million visitors in 2017. The diocese and the public institution expect to receive "14 to 15 million" after the reopening, which will be accompanied by new signage, a redesigned traffic plan and an online reservation system.
As they enter the cathedral, worshipers and visitors will discover a clean central axis, brand new minimalist liturgical furniture in brown bronze, a contemporary reliquary wall in cedar wood and glass paving stones forming a halo and housing Christ's crown of thorns, and a luminous cathedral.
The walls, dirty by fire and time, have regained the blondness of their stones.
Looking at the renovated cathedral is "a wonder," Jost said.