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. Look at the organ pipes carefully.
This presentation is mainly about the length of pipes and the different pitches of the notes they produce. In principle, each note on the keyboard needs a separate pipe. The critical measurement determining pitch is the distance between the mouth and the top of the pipe.
In what ways are the pipes different?

3. ♪ The picture shows just 6 pipes.
The pitch of the sound from an organ pipe depends upon its length. Low notes come from long pipes.
High notes come from short pipes.
Most organs have 5 octaves = 61 notes.
♪ The picture shows just 6 pipes.
How many should there be altogether for all the keys?

4. ♪ What is the main difference in the sound given by these six pipes?
The picture shows the names of the notes on the white keys. Notice how the 6 pipes shown give notes called ‘C’.
As the pipe gets smaller, the pitch becomes higher. For these six pipes the pitch rises by one octave from each to the next. This is because the length halves from each to next.
♪ What is the main difference in the sound given by these six pipes?

5. ♪ Why do we say that the notes from these pipes are an octave apart?
To play all the white notes from one ‘C’ to the next, you need 8 pipes.
Need help?
Click on Ollie.
Musicians always count the first and last note when describing an interval between two notes. Thus 8 notes is called an octave.
♪ Why do we say that the notes from these pipes are an octave apart?

6. Ollie can easily count a whole octave!
An octopus has 8 tentacles (legs, toes or fingers)
The only connection with an octave is the number 8!
Why?

7. Can you name these shapes?
Another 8 connection: octagon
Left: The octagonal lantern at Ely Cathedral
Right: An octagonal table top.
Think of an octave!

8. .... and then another, an octave higher or lower.
♪ Try humming a note ....
The octave is the simplest of musical intervals and getting children to hear this is an important aural skill.
For younger children it is less easy than it seems, but by demonstration they can be taught to recognise the octave.
The pitch of the first note is critical in determining how easy the second note is to find.
It may be easily demonstrated with any musical instrument available.
.... and then another, an octave higher or lower.

9. ♪ Work out the lengths of each of the other pipes in feet.
For a pipe to sound an octave higher, the length of the pipe from the mouth to the top has to be half as much.
For the longest pipe this length is 8 feet.
8 feet
In feet: 4, 2, 1, ½, ¼
♪ Work out the lengths of each of the other pipes in feet.

10. ♪ Work out the lengths of each of the other pipes in centimetres.
For a pipe to sound an octave higher, the length of the pipe from the mouth to the top has to be half as much.
For the ‘middle C’ pipe this length is 60 cm.
60 cm
In centimetres: 120, 60, 30, 15, 7.5
♪ Work out the lengths of each of the other pipes in centimetres.

11. ♪ How many ranks of pipes
A complete set of pipes is called a rank.
It is normal for organs to have several ranks which can be played from one keyboard (manual).
5 ranks are visible, not counting the larger display pipes to the right.
Some of the ranks are arranged in double rows. The external colour of the pipes is the most distinguishing feature in this photo.
♪ How many ranks of pipes
can you see in this photo?

12. ♪ Compared with an 8ft rank,
A rank starting with 8 feet for the lowest note gives
sounds at normal pitch.
Notice that most of the pipes in the photo are much shorter. For some ranks the longest pipe is only 4 feet or 2 feet or even 1 foot. When this is so, the whole rank sounds higher in pitch.
One octave higher
♪ Compared with an 8ft rank,
how many octaves higher
does a 4 ft rank sound?

13. ♪ How many octaves higher
A rank starting with 8 feet for the lowest note gives
sounds at normal pitch.
♪ How many octaves higher
does a 2 ft rank sound?
♪ Some ranks start with a
16 ft pipe. How does this
type of rank sound?
Most organs have a 16ft rank for the pedals giving a deep bass sound.
2 ft: Two octaves higher
16 ft: One octave lower

14. ♪ How many combinations can you make from 8ft, 4ft and 2ft stops?
On the console, the length of the longest pipe is shown on the stop knob. The stops allow the organist to select different combinations of ranks at different pitches.
By combining a few stops you can make a variety of new sounds.
♪ How many combinations can you make from 8ft, 4ft and 2ft stops?
Organists generally use 8, 8 + 4, 8 + 2, ; i.e. Four combinations
4 + 2 is also possible but rarely used because a foundation tone of 8 ft is normally required.
However by playing an octave lower, 4 ft can serve as a foundation.
Haydn wrote a set of pieces for a musical clock (with pipes) which can sound charming on a single 4ft flute tone.

15. ♪ What is the length of the bottom note
Some stops give a sound which is in between octaves. For example,
the Twelfth sounds at a pitch twelve notes above a normal 8ft stop.
♪ What is the length of the bottom note
for the Twelfth?
♪ In the photo, find a stop which sounds an
octave below the Twelfth.
♪ What is the length of its bottom note
pipe?
Twelfth bottom note: 2 2/3 feet
Quint bottom note: 5 1/3 feet
These lengths might at first seem rather strange, but the arithmetic is really rather simple:
2 2/3 = 8 / 3 (3rd harmonic of 8ft tone)
5 1/3 = 16 / 3 (3rd harmonic of 16th tone)
Harmonics are the natural frequencies present in the tone of any musical sound.
1st harmonic is the fundamental frequency which determines the pitch of a note.
2nd harmonic is twice the fundamental frequency, an octave higher.
3rd harmonic is three times the fundamental frequency, twelve notes higher (octave + fifth)

16. This photo shows the inside of one of the largest organs in the world which has a total of 28,000 pipes.
This is the interior of one of the divisions of the Wanamaker organ in Macey’s store in Philadelphia, USA. The original owner of the store, a John Wanamaker, bought the large organ originally built for the St Louis Exposition. He installed it in the 7 storey atrium of his department store, but for several years kept on adding further pipes and divisions to make it louder. Recitals are still regularly held and broadcast on the radio and Internet.

17. ♪ Can you think of a reason for the smallest pipes being placed
in the middle?
This arrangement provides convenient access for maintenance purposes. From time to time each individual pipe needs to be tuned by adjusting the metal sleeve on the top of the pipe. Imagine doing this for 28,000 pipes!

18. ♪ What effect would the man in the photo hear if you played each
note, one at a time, starting from the lowest note and finishing at
the top?
In the CATO workshop children listen at close range to a chromatic scale (black and white notes in succession) played from the bottom note to the top. The stereophonic effect of pipes sounding alternately from left and right of the display case is distinctly audible. This alternate symmetrical arrangement of the pipes is almost universally employed, so the man in the picture would hear the same alternating effect as did the children. For tuning purposes, the tuning assistant at the keyboard would not play a chromatic scale, but would play a descending scale on every other note, first on one side and then on the other. This helps the tuner to avoid getting a stiff neck!

19. What have you learned? Octave Long pipes Short pipes Rank of pipes
Low notes
High notes
This slide may be used for revising the points covered in this topic.
Stops
16 ft, 8 ft, 4 ft, 2 ft pipes
Manuals
Pedals

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

21. 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:

22. Copyright notice
Copyright owner:Derby & District Organists’ Association
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The work may be copied by not-for-profit organisations for educational use, provided due attribution to the copyright owner is given.
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