The pipe organ, with its impressive range of nine octaves, features pipes of various sizes, types, and materials. Each pipe produces a unique sound, owing to its distinct design and composition.
This article explores the types of organ pipes, the materials used to make them, and the purpose of different sizes and styles. Discover how each element impacts the sound and function of the organ. Gain insights into what makes these musical instruments unique. Let’s delve into the fascinating aspects of organ pipes and how they produce such varied tones.
At a Glance: Organ Pipes
- Types of Pipes: The main categories are Flue Pipes and Reed Pipes. Flue pipes use air forced through a channel, while reed pipes use a vibrating reed, similar to a clarinet.
- Sub-categories of Flue Pipes: These include Principal (diapasons), Flute, and String pipes. Each offering varying tones from iconic organ sounds to imitations of string instruments.
- Pipe Design: Pipes are mostly cylindrical but also come in conical and rectangular shapes. The design impacts the resonance and harmonics of the sound produced.
- Materials Used: Common materials include metal alloys and wood, affecting tonal quality. Alternative materials like plastic, glass, and bamboo are also used for specific characteristics.
- Sound Variations: The diameter and length of pipes influence the sound’s tone, with wider and longer pipes producing deeper notes and thinner pipes producing higher pitches.
The Basics of Organ Pipes:
Organ pipes are cylinders that produce musical notes when air passes through them. The length, diameter, and material of the pipe affect the tone and timbre of the notes.
A rank consists of a set of pipes covering a full musical scale. Placing multiple ranks together creates a stop.
What Are the Two Main Types of Pipes?
The two main types of organ pipes are called Flue Pipes and Reed Pipes.
Reed Pipes:
Reed pipes function similarly to a flute or clarinet. A vibrating reed changes the air to create sound.
Reed pipes come in two styles: Solo Reeds and Chorus Reeds.
Solo Reeds work well in chorale pieces and can be effective when used alone in their own ranks.
Chorus Reeds are louder and frequently enhance the sounds of other stops.
Flue Pipes:
Flue pipes work like a recorder. They force air through a fipple, directing the air to produce sound.
Flue pipes contain no moving parts in their construction.
Unlike Reed Pipes, Flue pipes produce three types of sound: Principal, Flute, and String.
- Flue Pipes and Reed Pipes
- Reed Pipes: Solo and Chorus
- Flue Pipes: Principal, Flute, String
What Are The Differences in the Three Types of Flue Pipes?
Principal Flue Pipes:
These pipes, known as diapasons, are the most recognizable organ pipes and often the most visible.
Principals are often the main stops of the organ.
Many performers prefer these pipes to accompany choral performances.
Flute Flue Pipes:
Flute pipes usually have a larger diameter, which helps create a warmer tone.
These come in various shapes to create different sounds. Some examples are the triangular flue pipe and conical pipes.
These pipes are essential for lyrical organ music. They are also said to have a ‘playful’ tone.
String Flue Pipes:
String pipes imitate the tones of string instruments like violins.
The pipes are typically the thinnest in the organ.
These produce softer notes, often essential for performing classical movements.
- Principal Flue Pipes: Recognizable, main stops, preferred for choral
- Flute Flue Pipes: Larger diameter, various shapes, playful tone
- String Flue Pipes: Imitate strings, thinnest, softer notes
What Are Open and Closed Pipes?
Closed pipes have one end sealed off. This is also called a ‘stopped’ pipe.
Pipes open at both ends are referred to as open pipes.
Each one reflects sound waves differently based on the air vibrations’ frequency.
The closed and open ends of the pipes produce different harmonics and variations when a musician plays.
- Closed pipes: one end sealed
- Open pipes: both ends open
- Different harmonics
What Are The Different Shapes of Organ Pipes?
Most pipes are upright cylinders, but not always. Flute pipes often come in special shapes to produce unique tones.
Some, like the triangular flue pipe, are specialized. Others appear in many instruments.
Cylindrical:
The most common and iconic form of pipes, these pipes are the core ranks and stops of pipe organs. They are essential for producing the characteristic sounds associated with these instruments.
The sizes vary from a pencil’s dimensions to the largest pipe, which is 64 feet long.
Conical:
Conical pipes serve as supporting tones in the bass, middle, and treble ranges.
Conical pipes make excellent instruments for accompaniment.
Experts say that the conical shape reduces resonance compared to the standard cylindrical form.
Rectangular:
Rectangular pipes are not often found.
Sound travels differently in a rectangular pipe compared to a circular one, creating a unique tone.
Without specific proportions, the sound transmits unevenly, resulting in lighter tonal effects.
Many rectangular pipes are flue pipes.
- Cylindrical: Core ranks, essential sounds
- Conical: Supporting tones, reduced resonance
- Rectangular: Unique tone, lighter effects
How Do Different Diameters Change the Sound?
The pipe’s diameter affects the sound in two distinct ways.
Bigger pipes produce a more flute-like tone.
Mid-range diameter pipes produce a diapason tone.
Thinner diameter pipes generate a more string-like tone, similar to violins and cellos.
Some say varying widths produce different harmonic ranges.
Wider diameters produce fewer harmonics, while thinner diameters offer a richer variety of harmonics.
- Diameter affects sound
- Bigger: Flute-like tone
- Thinner: String-like tone
How Do Different Lengths of Organ Pipes Change the Sound?
Bigger and longer pipes create a lower, deeper sound. These pipes make up the core of the bass range.
Thinner and shorter pipes create higher treble notes.
What Different Materials Can Organ Pipes Be Made Of?
In theory, organ pipes can be made from nearly any material, such as stone, porcelain, ivory, glass, plastic, bamboo, and even paper.
The most common materials for organ pipes are metal and wood because they offer greater resonance.
What Kind of Metal is Used in Pipe Organs?
Traditionally, organ pipes are made from a lead/tin alloy in different percentages. Lead increases rigidity, while tin and other metals add unique tonal qualities.
Here are some of the most common alloys used in organ pipes, according to manufacturers:
30% tin, 70% lead – common metal
50% tin, 50% lead – spotted metal
75% tin, 25% lead – plain tin
6% antimony, 94% lead – Antimonial lead
Zinc is mainly used for large bass pipes.
These alloys also often include trace amounts of metals like copper.
In the 11th century, copper pipes started being used to enhance the organ’s tonal brilliance.
Since the 1900s, high purity copper, zinc, and aluminum alloys have been used in organ pipes to make larger ones. These alloys also improve tonal transitions in other pipes.
Metal pipes are polished, washed, or shined for a visual effect.
- Lead/tin alloy for rigidity and tone
- Zinc for large bass pipes
- Copper for tonal brilliance
What Kinds of Woods Are Used to Make Pipe Organs?
Pipe organs use various types of wood for their pipes. Thin planks are glued or lacquered to create the pipes.
Most wooden pipes are usually rectangular, but there are exceptions.
The type of wood affects the tonal qualities.
Experts in organ pipe making say that soft woods like pine and fir give a mellower tone.
Harder woods like oak and poplar produce clearer and stronger harmonics in bass lines.
- Various woods for pipes
- Wood type affects tone
- Soft vs hard woods
What Are the Uses of Other Materials in Pipe Organs?
Plastic, glass, bamboo, and other materials are sometimes used in pipe organs. These materials are often found in rare pipe organs rather than the usual wood and metal.
Plastic Pipe Organs:
Plastic is a popular choice for DIY homemade pipe organs. Most often, builders choose plastic PVC pipe for their projects.
Plastic pipes resonate well and are straightforward to cut to the right height. PVC pipe organs typically feature a closed pipe setup.
Finding different widths is straightforward and helps achieve varying resonances.
Plastic PVC pipes are excellent for creating an affordable home instrument.
Glass Pipe Organs:
Glass pipe organs are rare because the material is so delicate. Most glass pipes serve mainly as decorations.
Glass produces high, pure tones, often heard in common glass instruments.
Ivory in Pipe Organs:
Ivory, much like glass, serves mainly as a decorative touch on pipe organs.
In Germany, a unique instrument called the ‘bird cry’ is crafted using a combination of ivory and wood.
Bamboo in Pipe Organs:
The Philippines hosts the oldest and most notable bamboo organ. Bamboo’s natural hollowness and resonance make it unique.
It was initially chosen for its local availability and has acoustic qualities akin to wood.
Why Use Alternative Materials for Organ Pipes?
Sometimes, alternative materials are picked for their visual appeal. Others are selected to explore new tones and harmonics.
Others are selected for availability, for use in homemade or locally crafted instruments.
- Visual appeal
- New tones and harmonics
- Material availability