2. Mid of Philippe Lefebvre, Notre-Dame Cathedral organist, taking seat at organ
3. Various of Lefebvre's playing "Piece Heroique" composed by Cesar Franck
4. Wide of organ pipes
5. Mid of organ pipes and wooden structure
6. Wide of visitors listening to organ and taking pictures
7. Close-up of Lefebvre playing
8. Close-up of Lefebvre's feet pushing pedals
10. SOUNDBITE: (French) Philippe Lefebvre, Organist, Notre Dame Cathedral:
(talking about his first time listening to an organ, at 15:)
"I was here, on this organ's loft. I saw the organist and I was very impressed. I thought that there were much more possibilities than with a piano. Even though I find a piano magnificent, this is just a whole new world."
11. Close-up of Lefebvre's hands
12. Mid of Lefebvre with music sheets
13. Close-up of music sheets of "La Piece Heroique" by Cesar Franck
14. SOUNDBITE: (French) Philippe Lefebvre, Organist, Notre Dame Cathedral:
"We improvise. It is a big tradition in French organ school, for centuries. Since music sheets didn't exist at the early stages of the organs. So organists were improvisers primarily. And this tradition went on, in Europe and particularly in France."
15. Mid of Lefebvre's feet pushing organ pedals
16. Close-up of organ tubes
17. Tilt up of Lefebvre playing organ
18. SOUNDBITE: (French) Philippe Lefebvre, Organist, Notre Dame Cathedral:
"Notre Dame is different because it is one of the only organs that has kept the traces of the centuries. As has the cathedral itself. So we have some tones from before the Revolution, some from the 19th century similar to ones of a symphonic orchestra and also all the recent inputs from the 20th century. So we have three or four authentic centuries of music."
19. Close-up of deep gash in organ wood carving, AUDIO: music
20. Wide of organ, AUDIO: music
21. Close-up of carved wood, 18th century and 19th century vertical tubes, AUDIO: music
22. SOUNDBITE: (French) Philippe Lefebvre, Organist, Notre Dame Cathedral:
"This particular organ was always looked after by the cathedral and more recently by the French state. Every thirty years this organ was restored, in order to keep its good condition but also to add some improvements and some newer tones. And these tones are made for Notre Dame Cathedral's acoustics. He is in total harmony with Notre Dame Cathedral's acoustics. He rings out the walls of the cathedral."
23. Wide tilt down of cathedral, AUDIO: organ music
24. High shot of visitors inside cathedral, AUDIO: organ music
25. SOUNDBITE: (French) Philippe Lefebvre, Organist, Notre Dame Cathedral:
"Here in Notre Dame when you play a tone, the acoustics make the resonance last for eight to nine seconds. It is exceptional, the sound spreads across the whole structure and you feel it when you play, the sounds come back at you. It doesn't just stop immediately. It provokes sensations for the organist."
26. High shot of Lefebvre playing organ
27. Wide exterior shot of Notre Dame Cathedral, installation in foreground marking its 850th anniversary
28. Mid of visitors walking to cathedral
29. Wide of crowd in front of cathedral
30. Mid of queue of visitors
31. Wide of visitors seated in front of cathedral
32. Low exterior shot of cathedral
33. Close-up of sculpture representing a French King
Notre Dame Cathedral in Paris has allowed rare access to its historic organ.
The instrument has been refurbished for the first time in three decades.
The make-over is to mark the cathedral's 850th anniversary this year.
From the moment the teenage musician caught sight of the organ in France's most famous cathedral, he knew where he wanted to play.
In the five decades since, Philippe Lefebvre has travelled the world to play what he describes as an "orchestra of one," but the organ master returns to the loft above Notre Dame Cathedral and is never disappointed.
He has none of the infamy of Notre Dame's bell-ringer and is invisible to the thousands of visitors Notre Dame receives each day.
But Lefebvre says he never misses the direct contact with his audience that so many musicians crave.
For the 64-year-old, it is enough to be the caretaker of what he considers an almost otherworldly instrument.
He first saw it when he was 15, as a young piano student.
"I saw the organist and I was very impressed. I thought that there were much more possibilities than with a piano. Even though I find a piano magnificent, this is just a whole new world," says Lefebvre.
A few visitors may notice the biggest pipes above the entrance, but most turn their eyes no higher than the stained glass windows along the sides.
Lefebvre, when he plays, is hidden even further - behind a brand new wooden-panelled control board that he compares to a cockpit.
A century ago, six strong men were needed to pump enough air for the music.
Now, there is an air compressor behind the scenes, and the newly rebuilt instrument itself has a touch-screen panel that can note "favourite" stop combinations like a browser bookmarks a Web page.
Despite the advances in organ technology, Lefebvre feels the weight of history in his job.
There are deep gashes in the wood carvings of the organ loft - a legacy of revolutionaries from the late 18th century who slashed away the fleur-de-lis symbol of the monarchy.
But, Lefebvre says, they refrained from melting down the metal pipes into bullets during the war after heeding pleas from Notre Dame's organ master, Claude Balbastre, who had adapted to new political realities by composing variations on the Marseillaise anthem.
As part of the refurbishment, each of the nearly 8,000 pipes - some of which date back to the 18th century - was individually cleaned and returned to its place.
The new electronic panel, five cascading keyboards and more than 200 stops were installed.
In cavernous Notre Dame, the organ's location is unparalleled.
When Lefebvre plays the opening of "Piece Heroique" a few tourists turn toward the sound.
By the end of the grandiose piece, the wooden floor of the loft is vibrating and Notre Dame's arched ceiling echoes with the sound.
The big organ is played on weekends and for major ceremonies and holidays, the playing shared by three organists who have held the job since 1985.
As organs employ the sounds of a multitude of instruments, it is usually up to the organist himself to decide the combination of stops he wants for any given piece.
That decision can change according to the organ, the space and improvisational whim.
"Since music sheets didn't exist at the early stages of the organs. So organists were improvisers primarily. And this tradition went on, in Europe and particularly in France," says Lefebvre.
Lefebvre can bring back 5,000 different combinations of stops with the new electronic memory.
Things have changed since the keyboard was connected to the pipes by long mechanical arms.
And the organists themselves aren't tied to any one instrument.
Lefebvre says he has played thousands of organs around the world, gleaning something from each one.
Still, Notre Dame remains his ideal as it was when he was young.
"Here in Notre Dame when you play a tone, the acoustics make the resonance last for eight to nine seconds," he says.
"It is exceptional, the sound spreads across the whole structure and you feel it when you play, the sounds come back at you. It doesn't just stop immediately. It provokes sensations for the organist."
According to tradition, Notre Dame's first stone was laid in 1163.