Ever since the days of the first cave people, music has been part of our lives.
But what is music?
And what makes a sound, sound musical?
 |
Music under the microscope A few short notes |
|
|
Doh Ray Me… Soh fah, so good for musical scales |
|
|
Techniques 1 & 2: Plucking and bowing Meet some stringed instruments and give them a twang |
|
|
Technique 3: Blowing Say hello to brass and woodwind instruments |
|
|
Technique 4: Banging Percussion instruments to shake, rattle and bash |
|
|
Resonance Find out how you can shatter a wine glass by singing to it! And why this explains how instruments make music … |
|
|
Timbre And Harmony Why a guitar doesn’t sound like a trombone.. |
Music under the microscope
No one can say exactly what music is, and many arguments have been had and friendships lost along the way …
Music can loosely be thought of as a collection of non-random sounds that have been organized in a recognisable way, and might repeat every so often.
Some people would say that ALL sounds have some musical merit - even dogs barking, dustbin lids crashing, or vacuum cleaners.
Doh ray me
A musical note is a sound of a particular frequency. So for example, the note middle C on a piano keyboard has a frequency of about 262Hz.
Something interesting happens when you double the frequency of the note:You get a new note which sounds like it’s related to the lower sounding one, but is an exact octave higher.
In western music, there are six notes between these two C notes - D, E, F, G, A and B in a family called a scale. They’re also known to their friends as Doh, Ray, Me, Fah, Soh, La, Ti and Doh. In between these notes there are also some half notes called flats and sharps.
Playing combinations of these notes is the first step to creating music. Now we need a band.
Techniques 1 and 2: plucking & bowing
Stringed instruments such as violins, guitars, harps, pianos and even underpants can produce music if you twanging a tight string – try it.
Plucking, hitting or sliding a bow across the stings them make them vibrate, and as the strings make the air vibrate, it creates the musical note.The different notes are produced depending on the length and thickness of the string, and the tension (how much you’ve stretched it).
And of course twanging the sting strongly will produce a louder note than if you just gave it a little tickle.
Technique 3: blowing
If plucking a string makes you want to blow raspberries then you may be perfect for playing a brass instrument such as a trombone, a trumpet or a tuba.
Blowing into the cup-shaped mouthpiece sets a column of air inside the tube vibrating – and it’s made louder by the flared end of the tube, in the same way that shouting down a traffic cone will make your voice sound louder!
Pressing the valve buttons on the instruments (or sliding the tube of a trombone) makes the length of the column of air shorter or longer and this is how the different notes are produced.
Wind instruments such as oboes, bassoons and clarinets work in a similar way but the mouth piece has a reed (or reeds) that’s set to vibrate as air is blown past it. This makes the air vibrate in the column.
If you want to try a very simple version of this, try this activity .
Technique 4: banging
If plucking and blowing make you want to bang your fists, then don’t worry you can still be a musician…
Percussion instruments like drums, tambourines and pianos produce sounds by being hit, shaken or scraped.They’re either tuned or untuned. Tuned ones like pianos and xylophones play specific pitches or notes, while untuned instruments like drums produce a sound with an indefinite pitch, like the sound of a hand knocking on a door.
Some people are surprised that pianos are called percussion instruments, but look inside one and you’ll see why. When you press a key a hammer hits a string inside. That’s what makes it percussion.
A harpsichord, on the other hand, looks like a piano, but its notes are produced by strings being plucked, so it’s part of the stringed section.Untuned instruments such as drums are made from a thin membrane that’s been stretched over a hollow frame. Hitting the membrane with your hand or a stick, makes it vibrate and produces the sound.
Different shapes and different materials of drums make may different sounds.
Resonance
All instruments (and indeed all objects) have a natural frequency or set of frequencies at which they vibrate when struck, plucked, strummed or made to shake.
The actual frequencies depend on what material the object is made from and the shape and size of the material. If a sound wave hits an object with the right natural frequency it will cause it to vibrate. And this will produce a sound.This is called Resonance.
When a flute is blown into, a single resonant frequency is produced (depending on which note is being played). This gives a very pure ‘smooth’ sound. Other instruments – especially percussion and brass - produce more complex sets of frequencies that make a less smooth sound.If a singer produces a note at the same frequency as the resonant frequency of say a wine glass, they can set up vibrations in the glass itself. If they sing loud enough, they will produce larger vibrations and can shatter the glass!
Timbre
If you play the same notes on different instruments they don’t sound the same do they?
The reason for this is that rather than producing only one frequency of sound wave, each instrument also produces other quieter frequencies, called harmonics.Each instrument produces a unique combination of frequencies, which give it its characteristic sound. This is called its timbre.
Notes are said to be in harmony when some of the harmonics of each note share a frequency.
Go back