<< Chapter < Page Chapter >> Page >

Keys

In general, the more holes that are closed with a key or covered by a finger, the longer the standing wave inside the instrument, and the lower the pitch.

Valves are more commonly found on brass instruments. Pressing a valve makes the air flow through an extra section of tube, temporarily making the instrument longer in between the mouthpiece and the bell. The slightly longer instrument gets a slightly lower fundamental harmonic , and a lower harmonic series . (A few valves are ascending valves , which cut off a section of tubing and so raise the pitch.) Press the button in this animation to see how the air gets redirected through one type of ( descending ) valve.

Valves

The figure and the animation show one type of piston valve. Other styles of valves, including rotary valves as well as other types of piston valves, have different arrangements for the air flow inside the valve, but the purpose is always to redirect the air when the valve is pressed, opening up or cutting off a section of tubing.

Most brass instruments can play an entire chromatic scale with just a few valves. They use small changes in the embouchure to get many different notes from the harmonic series for each valve. But woodwinds have many more keys and fingerings available. Typically a woodwind can play the notes in an entire octave just by changing fingerings. Then a large change in the airstream and embouchure is needed to switch to the next harmonic , so that the next octave can be played. This big change is called overblowing .

Some brass instruments may also have a spit valve , a small hole that is normally closed but that the player can open quickly with a small key. This is not used while playing the instrument. It is used to empty the instrument of what players call "spit". Water vapor from the warm, moist breath of the player condenses in the instrument, especially when it is cold. (And, yes, there's probably a little actual spit in it, too, but not much). This can cause a bubbling sound in the tone. The spit valve is placed at a spot where the water naturally accumulates (due to gravity), giving the player a way to quickly empty the instrument during rests.

Wood and brass: instrument materials

Calling the two main wind sections of the orchestra woodwinds and brass is a bit misleading. The important difference between the two groups is how the sound is first produced, not what the instrument is made of. (In a "brass" instrument, the lips are buzzed against the rim of the mouthpiece. In a "woodwind", the sound begins either with one or two vibrating reeds, or at a sharp edge in the mouthpiece.)

"Brass" instruments are usually made of brass, an alloy of copper and zinc. They may be the normal color of brass metal, or they may be tinted to a different metallic color. For example, nickel may be added to the alloy to give the instrument a silver color. Occasionally brass instruments are not made of metal at all; for example, the sousaphone, a tuba used in marching bands, is often made of (lighter-weight) fiberglass.

"Woodwinds" are often made of hardwood, but saxophones are normally made of brass, and most orchestral flutes are made of "nickel-silver" brass. There are also good-quality plastic woodwinds that may be preferable to the wooden versions in some situations - for example, playing in rain, heat, or cold.

Other materials are often needed to make an instrument work well. Felt pads, pieces of cork, metal keys, and various oils help to keep the valve and key action quiet while keeping the instrument from leaking air in the wrong places.

Questions & Answers

What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
China
Cied
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Privacy Information Security Software Version 1.1a
Good
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get the best Algebra and trigonometry course in your pocket!





Source:  OpenStax, Understanding your french horn. OpenStax CNX. Apr 03, 2006 Download for free at http://cnx.org/content/col10219/1.4
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Understanding your french horn' conversation and receive update notifications?

Ask