1. Exploring a Pipe Organ with CATO
Derby and District Organists’ Association
Exploring a Pipe Organ with CATO
Notes for teachers appear in this panel.
Children and the Organ Project

2. Each organ pipe can only produce one note and this has to be at a fixed loudness.
To make the music louder or softer, the player cannot simply press the keys harder or more gently as one does on a piano.
The ‘feel’ and function of an organ keyboard is fundamentally different from that of a piano.
Organ:
On a mechanical action organ, the keys are connected to the individual pipes by a system of levers which sometimes demand strong downward pressure.
A pipe sounds continuously while a key is depressed. There is no control over loudness.
The release of the key requires more precise control than with a piano.
There is no equivalent of a piano’s sustaining pedal, so organists learn how to play a series of notes ‘legato’ (joined up) without any gaps between the sounds.
Piano:
1. The key is connected to a hammer which hits a string momentarily.
2. The sound gradually dies away after striking a note.
3. The downward force on the key determines the loudness of the sound.
4. The sustaining pedal is used to achieve ‘legato’ playing.

3. There are four main methods of controlling the loudness:
1. Choosing a loud, medium or soft stop
2. Combining several stops
3. Changing manuals (keyboards)
4. Using the Swell pedal

4. ♪ Click on each stop to hear its sound.
Choosing one stop
Organists have to learn which stops are soft and which are loud. For example, in general, Diapasons are louder than Flutes but they are not as loud as the Trumpet stop.
DULCIANA 8
ROHR
FLUTE
CLARIBEL
OPEN
DIAPASON
The stops have different loudness, but the tone of the sound is also different.
♪ Click on each stop to hear its sound.
♪ As well as loudness, what is the other difference in sound for each stop?

5. ♪ Click on each stop to hear its sound.
In the reed family, there is a large range of loudness, starting with the Oboe and going up to the Tuba.
OBOE 8
HORN
TRUMPET
TUBA
Reeds stops are generally louder than flue stops. As with flues, stops have different loudness, but the tone of the sound is also different.
♪ Click on each stop to hear its sound.
♪ As well as loudness, what is the other difference in sound for each stop?

6. Combining several stops
Pulling out two stops, then three stops and so on is the easiest way of making the organ sound louder, but the player has to take care in choosing the extra stops.
If you are not careful, the resulting sound could
sound very ‘muddy’ or very harsh and unbalanced.
You need to have at least one 8 foot stop, but only
two or three more at 8 foot pitch.
It is more effective to add
brightness with 4 ft stops and
other higher
pitched stops.
As in the previous examples, these combinations not only give different loudness, they also vary in tone, becoming generally brighter in this example.

7. The button at the left hand end gives the softest combination.
To help the organist add stops quickly and in good combinations, there are special ‘selector’ buttons underneath the manuals.
The button at the left hand end gives the softest combination.
As you press buttons to the right, more and more stops are added.
Softest combination Loudest combination
Pressing these buttons in turn from left to right is a very useful way of making the organ gradually louder.
Organs vary in their mechanical aids or ‘accessories’ for making the selection of stops easier. In this example the buttons activate electro-magnets which push the stops in or out in combinations which have been pre-set.

8. ♪ Notice the small selector buttons underneath each manual.
Liverpool Cathedral has the largest organ in the UK.
At the console, there are plenty of stops to choose from!
♪ Notice the small selector buttons underneath each manual.
Combination pistons for selecting stops are indispensible in large organs.

9. Here is a closer view of these selector buttons
Here is a closer view of these selector buttons. They are called ‘Thumb pistons’ because they are usually pressed with the thumb.
If both thumbs are too busy playing notes, then there are some similar ‘Toe pistons’ just above the pedal board.

10. (Hint: Think about the tone as well as loudness of the stops.)
Changing manuals
A convenient way of very quickly changing the loudness is to switch from playing on one manual to playing on another one.
♪ Explain how the organist would choose stops for each manual to change the loudness.
♪ What useful effect can the organist create with one hand on one manual and the other hand on a different manual?
(Hint: Think about the tone as well as loudness of the stops.)
Each manual might have a different combination of stops, differing in loudness and tone. A quick change of manual allows sudden changes of loudness.
A common effect is to play a tune on one manual with a loud stop against an accompaniment on the second manual.

11. Using the Swell pedal
Organ builders have invented
a simple way of controlling
loudness by placing the pipes
for one manual inside a large
cupboard called a ‘Swell Box’.
As you open or close the doors
on the front of the Swell Box,
the loudness changes. The
Doors are designed in narrow
sections and controlled by
levers to a special foot pedal
on the console.
The use of the Swell pedal is the only way an organist has of making gradual changes to the loudness. When the foot is on the pedal, a push forward with the toes opens the Swell box; a push down with the heel closes the Swell box.
♪ Explain how the organist would choose stops for each manual to change the loudness.
♪ What useful effect can the organist create with one hand on one manual and the other hand on a different manual?
(Hint: Think about the tone as well as loudness of the stops.)

12. ♪ Explain how the Swell pedal is used to make a crescendo.
In music, the terms crescendo and diminuendo are used to describe changes of loudness.
♪ Explain how the Swell pedal is used to make a crescendo.
♪ Click on this button to hear a Swell crescendo.
♪ How would you use the Swell pedal to make a diminuendo?
♪ Click on this button to hear a Swell diminuendo.
♪ What is the musical word for playing music very softly?
Use of the Swell pedal is the main means by which an organist can produce gradual changes of loudness. As the box is altered, the tone also varies: the bright tones are quietened more than low pitched tones.
Crescendo = gradually getting louder
Diminuendo = gradually getting software
Pianissimo = very soft
♪ Explain how the organist would choose stops for each manual to change the loudness.
♪ What useful effect can the organist create with one hand on one manual and the other hand on a different manual?
(Hint: Think about the tone as well as loudness of the stops.)

13. The organ sounds louder when you pull out more stops.
What have you learned?
The organ sounds louder when you pull out more stops.
You cannot make the organ sound louder by pressing harder on the keys.
The Swell organ is in a large box with shutters which open and close.
This slide may be used for revising the points covered in this topic.
Different stops have different loudness.
The Swell pedal controls the shutters and loudness of the Swell organ.

14. Children and the Organ Project
Materials prepared by Laurence Rogers for the
Children and the Organ Project
Team:
Stephen Johns
James Muckle
Edmund Stow
Gillian Chatto
Laurence Rogers
John Forster
Chris Darrall
Sponsored by
Derby and District Organists’ Association

15. Children and the Organ Project
Derby and District Organists’ Association
Children and the Organ Project
The project aims to introduce young children to the fascinating world of pipe organs through practical workshops and fun activities. The building and playing of organs being such multi-disciplinary activities, their study has numerous spin-offs for the school curriculum.
For more information, visit our website:

16. Copyright notice
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