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The Fred J. Cooper Memorial Organ Experience

The Philadelphia Orchestra has received a $5 million gift from the Wyncote Foundation to increase and expand programming for the Fred J. Cooper Memorial Organ in Verizon Hall, the world’s largest mechanical action concert hall pipe organ. The partnership is supported by longtime friend of the Orchestra and former Board member Frederick R. Haas. The five-year initiative, entitled “The Fred J. Cooper Memorial Organ Experience,” will focus on artistic plans by Music Director Yannick Nézet-Séguin, in consultation with Artistic Advisor Frederick R. Haas, to feature the organ more extensively in season programming, help to build audience interest in the instrument, and educate audiences about the organ’s musical capabilities.

The Orchestra is featuring the Fred J. Cooper Memorial Organ to showcase the majestic instrument paired with the “Philadelphia Sound.” We are elated to be enhancing our season programming to allow for works that highlight this magnificent instrument.

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About the Organ

The Fred J. Cooper Memorial Organ, Dobson organ Op. 76, ranks as the largest mechanical-action concert hall organ in the United States. With its nearly 7,000 pipes, four blowers, 300 levels of memory, 111 stops, pipe sizes ranging from about the size of a drinking straw up to two feet square by 32 feet high, this is truly the King of Instruments!

Organ Facts

  • Largest Pipe: Built of wood, the largest pipe is approximately 2 feet square by 32 feet long.
  • Smallest Pipe: Built of metal, the smallest pipe is the size of a drinking straw.
  • Range of Wind Pressures: Three blowers totaling 25 horsepower supply the organ with air ranging in pressure from 4" to 25".
  • Instrument Total Weight: The total weight of the organ and its structure is approximately 32 tons.
  • Total Number of Pipes: 6,938
  • Levels of Memory: 300 (meaning thousands of preset combinations can be stored for the organists' use during performance)
  • Number of Combination Pistons: 48
  • Number of Toe Pistons: 22
  • Where does the Verizon Hall Organ rank in size?* 47th in the world (Interestingly, Philadelphia’s Wanamaker Organ is the largest fully functional pipe organ in the world.)
    *Based on total number of ranks.


Click below to hear the different sounds of the pipes

1' C of Great Principal 8'

2' C of Bourdon 16'

2' C of Posaune 16'

2' C of Chimney Flute 8'

8' C of Chimney Flute 8'

Glossary of Terms

The large unit where the organist sits to play and control the organ. This includes the keyboard or manuals, pedal board, pistons, and drawknobs or stops.

The pipes are grouped into several separate sections called divisions such as the Great, Swell, Solo, Positive, and Pedal. Each is controlled by its own manual or the pedal board.

Electric Key Action
In an electric key action, a wire, an electric circuit, and an electro-magnet cause the valve below each pipe to open and close. When you press the key, you close an electrical contact. Electricity flows to the circuit that causes an electro-magnet to open and close the valves under each pipe.

Mechanical Action (Tracker Action)
The key is connected to trackers (wooden, metal, or plastic strips or rods) that eventually connect to the valves that open to admit air from the wind chest into the pipe. When you press the key, you are physically opening the valve in the wind chest. In mechanical action, there is one valve for each note on the keyboard.

Note: The Verizon Hall organ has both electric and mechanical key action.

Organ pipes fall into one of four broad sound categories: principal, flute, string, and reed. The first three types are known as "flue" pipes and work like whistles. The majority of organ pipes are flue pipes. In contrast to the whistle-like flue pipes, the reed pipes work like clarinets or saxophones, but have a brass "tongue" instead of a cane reed. Some of the reed pipes are the loudest pipes in the organ.


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