The sections of the orchestra
If you drop a stone in a pond it makes ripples - or waves - that you can
see. If you drop a stone on a table it also makes waves, the difference is
that they are waves in the air. Air is invisible so you cannot see these
waves. But when they reach your ear you will hear a sound! All musical
instruments create sound waves in order to be heard but the instruments of
each section do this in a different way.
Strings
If you pull an elastic band or very thin piece of string tight and pluck
it will make a sound. If you stretch it over an empty box with a hole iin it
then it will be louder. The stringed instruments effectively do just this.
They play different notes by changing the length of the piece of string with
their left hands the effect of making the elastic band tighter or looser.
Finally rather than plucking the strings they usually pull a bow across them
this makes it possible to play much longer notes than if the string is
only plucked.
As we said earlier, the string section has groups of each instrument: two
groups of violins and one each of violas, cellos and double-basses. The
cellos and basses often play the same musical line but at different pitches
- the double-basses play much lower.
Woodwind
The woodwind players make the sound waves in a tube but they do this in
different ways. The flute, for example, blows across the top of the tube -
in much the same way as if you blow across the top of an open bottle. You
may also have discovered that you can make quite a loud noise by holding a
flat blade of grass in your hand and blowing across it. This is almost what
the other wind instruments do to make sound waves.
As with the strings changing the length of their strings, different notes
can be played by changing the length of the tube. Wind players do this by
using their fingers, plus metal rods which open and close holes in the sides
to make the tube shorter or longer.
The members of the woodwind section which are most often seen in
orchestras are:
- flutes, and their smaller relative, the piccolo, the highest pitched
instrument in the orchestra
oboes, and the larger cor anglais which has a mellow, rich sound.
- clarinets, and the related bass-clarinet
- bassoons, the lowest pitched of the wind instrument families, and the
related contra-bassoon, which plays even lower, at much the same pitch as
the double-bass.
Brass
The members of the brass section also make sound waves in a tube but in a
different way: by making their lips vibrate to start the sound waves moving.
They can make different notes by changing the length of the tube and the way
they use their lips.
The horns, trumpets and tuba change the length of the tube with valves, a
way to shorten or lengthen the tubing by pressing a button.
The trombone has a completely different way of changing the length of the
tube a sliding piece of tubing operated with the right hand changes the
length of the pipe.
Percussion
Percussion instruments all make their sound in the same way by hitting
something with something else and, depending on what is hit and what it is
hit with, they can make a variety of sounds. A huge variety of instruments
can be in this section of which the most common are drums, cymbals and
triangle.
There are drums of all shapes and sizes but only two types: those which
can make only one note and tuned drums which can play a variety. The most
common tuned drums are large copper ones called timpani or kettledrums;
these are the percussion instruments most commonly seen in orchestras. |