Plaisance du Gers

Cassagnac mill

General principles of the visit

Visitors will discover the organ components in 5 stages presenting interactive systems. Interactivity is direct and physical, meaning that the technology of the organ cannot be damaged. This represents a Hands-On Museum, where contact with the items described is not transferred to tactile screens. The visitor can touch ! Each stage introduces a particular element of the organ. This introductory course makes it possible to understand all the elements that go to make up an organ. Their coherence will become apparent at the time of immersion in the Monumental Organ; and later when visitors can play a small organ for themselves.

Each interactive system can be approached through three dimensions, each clearly recognisable.


This dimension enables visitors to experience for themselves technology or physical phenomena that have marked the evolution of the organ. These presentations have been developed to catch the interest of children and young teenagers, so they can participate directly in setting off technical processes or physical phenomena. Children and teenagers encounter phenomena – acoustic, mechanical, pneumatic, etc – which amaze the younger ones and provoke the curiosity of the older ones. In turn, the adults and older teenagers pass on the explanations that they have just discovered. Whether young or adult, each person can realise an experiential approach.

Two other dimensions then complement the experiential one: the scientific and the historical, both situating the experiential dimension in the context of the organ's evolution over 2,300 years of history.

The scientific and technical dimension

which enables visitors to discover the phenomena caused by the experiential dimension, to understand their practical impact on use of the organ, and to see how certain discoveries relating to the instrument's evolution generated other applications far beyond organ-building (such as the invention of keyboards, pressure regulation for gas-lighting, calculation of frequencies, the circular saw, etc).

The history and heritage dimension

which enables visitors to discover elements of heritage – such as archival documents, prints, antique publications - which make a direct link between the visit and significant moments in history, and also the sound aesthetics of the organ. There are in fact numerous correlations between the history of art and music and the evolution or invention of the elements of structure, technology, acoustics and décor of the organ..

At the end of the introductory course, there are two complementary units, featuring :

- the decoration of the side shutters of the organ, through the history of art.

- the work of great international organists, through films that reveal the virtuosity of musicians rarely heard in public (e.g. short films on concert performers, on organists from the period of silent movies, or on jazz organists…).

How the visit unfolds

Reception at ground floor

Visitors enter the Cassagnac Mill through a large doorway with a red-brick surround. The doors are kept open during hours of access to the public. They open into an atrium, with a glass partition that gives a view of the adjoining organ builders workshop. This trade is still alive and active in Plaisance du Gers.
A service door with a passcode gives access to the floor area of the organ builders workshop, and a decorative door opens into the visitors' reception area.

Start of the visit

The visit starts on the second floor. This level comprises firstly a mezzanine giving a bird's-eye view of the Monumental Organ, the first stage of the visit. This stage defines the subject: the ORGAN as an invention of genius of Ctesibios of Alexandria, in the third century BC. The organ is a musical instrument, consisting of :
- a keyboard
- a bellows
- wooden and metal pipes
A reconstruction of Ctesibios' organ gives a sense of the innovative quality of this invention.

Directly accessible from the second floor, there are 30-40 seats in fixed gradient rows, so the visitor can sit and listen when the Monumental Organ starts up automatically.

A small walkway gives access to a second mezzanine.
This passage displays a series of illustrated panels, tracing the historical evolution of the organ, from ancient times to the 16th century, the time when the instrument took on the form which is known today.
The panels are placed beside the walkway guard-rail, to reassure visitors of the safety of the crossing. The system has natural lighting from the windows, making it possible to use the reverse side of the panels (facing the organ) to create a portrait gallery of leading figures of the organ, composers, performers and builders.

The second mezzanine reveals two mysterious boxes jutting out, the façades being covered by shutters.
These are the two 'Swell Boxes' of the Monumental Organ, sealed compartments (except for the front) each filled with a thousand different pipes. The panels behind these two swell boxes, usually opaque, will be replaced by transparent glass walls that will reveal the multiplicity and diversity of organ pipes being used in the instrument.
This second stage of the visit gives a chance to discover – and experience – the acoustic and physical phenomena arising from the forms and materials of organ pipes. Behind the guard-rail of this mezzanine, the visitor will have a bird's-eye view over the Monumental Organ's forest of pipes.
One then reaches the first floor by a long staircase that gives a clear view of the portrait gallery.
At the halfway point, the staircase is on a level with the lower row of the gradient seats, which one can also reach when going down to the first floor.

Continuation of the visit to the first floor

At the foot of the staircase (or of the lift), visitors will discover an area that includes the part under the gradient seating. This is the third stage, devoted to sound transmission, the muscle system shared by all organs. The systems displayed allow action in different modes of transmission, and direct observation of how these phenomena work.

On the supporting wall of the gradient seating, there can be seen an enlargement on human scale of the famous drawing from the treatise of Dom Bedos de Celles, showing all the details of a cross-section of a 1770s organ. Visitors will find on this enlarged picture the elements already presented: a multitude of pipes, pallets and transmission mechanisms. They also discover what remains to be explored – the organist sitting at the keyboards and the movement of the bellows.

Leaving the area of sound transmission, visitors arrive at the fourth stage of the visit, devoted to the brain of the organ, the keyboard console.
Several types of keyboard consoles are displayed, until visitors discover the control panel of the Monumental Organ, a real modern dashboard.
The consoles area is next to the Monumental Organ itself, and the moment has arrived to experience the magic of the organ from the inside. A zigzag route has been created through the heart of the Organ, and the visitor almost doesn't know where to look, being surrounded by a multitude of pipes, bellows, conduits, levers and valves.

Every ten minutes, the organ starts up automatically. A countdown timer allows visitors to organise their own experience, depending on whether they want to listen from nearby or further away. They are given prior warning of the automatic start-up, so as not to be startled. The music played make it possible to hear strange and unusual sounds. The textures of sound is constantly evolving. The intention is not to create powerful sounds, but interesting and attractive ones. Visitors can experience the sound of an organ 'from the inside', trying to discover which are the pipes producing particular sounds. The musical interludes are short – no more than two minutes - so as not to prolong the tour too much, but also so as to arouse interest in hearing the next interlude in a different way.

The tour then gives access to an area in the rear, divided in two. First, the 'Bellows' area, the fifth introductory stage, which gives a chance to discover and experience the components and changes in an organ bellows. A second space is then made available as a sound-proof room, where the visitor has access to a small organ, all of whose components are visible. The instrument will allow the visitor to put into practice everything discovered on the technical level..After sitting down at a keyboard console, the visitor will try to manipulate the pedal, the levers of the stops, and the manuals…

From having been an observer, he becomes a participating musician !

You leave this experience by a walk through the Monumental Organ, allowing you to turn to face it and hear its sound with the perspective gained by the knowledge just acquired. One then returns to the ground floor using the stairs or the lift.

Continuation and completion of tour on ground-floor

At the foot of the stairs, visitors arrive at the 'Cabinets' area, which displays some typical large organ cabinets, reflecting stylistic developments through the ages.
Then visitors enter the video area, where videos are shown concerning two major types of activity around the organ :

The tour finishes in a Boutique.

A Temporary Exhibition space can be visited before leaving through the airtight exit door.

Occasional events at 'Cité de l'Orgue'

Tours have been planned to be compatible with usage of 'Cite de l'Orgue' for events, such as concerts, concert-films and conferences.

For events, reception will be organised in the same way as for public tours: reception in the atrium and access to the gradient seating by staircase or lift. The gradient seating is supplemented by a number of mobile seats , giving a capacity of around 80 seats – see the diagrams opposite. If needed, the public seating capacity can be supplemented by a row of self-locking chairs.

At the end of the concert or during an interval, the ground floor can easily become a 'foyer' area furnished with a small bar, encouraging socialising and continuation of the pleasure of the musical event.