Exeter Cathedral's unique 17th-century organ will be carefully dismantled this week as a £1 million restoration project gets under way.
The organ, including the pipes, is to be sent to experts Harrison and Harrison in Durham, who have looked after historic instruments since the 1930s.
The cathedral's director of music, Andrew Millington, said the restoration was overdue, with all organs needing a complete clean and overhaul every 25 years.
He said: "This intricate and time-consuming operation involves the dismantling of the instrument, including well over 4,000 pipes which have to be individually cleaned and repaired where necessary.
"The Exeter organ has evolved over the centuries since it was first built in 1665, and the original case now houses about four times the number of pipes than it did in the 17th century.
"The interior of the organ is extremely cramped, and some sections are virtually inaccessible for maintenance.
"The inside layout of the organ is to be completely re-designed with new sound boards and a better projection of sound into the building.
"Certain intricate moving parts such as delicate leatherwork will be replaced, and wind leaks rectified.
"The aim is to restore this historic and renowned instrument to perfect working order for future generations."
Fundraising to complete the £1 million project is ongoing. The organ will not return to Exeter until next year. In the interim, digital instruments will provide music.