Harmonics (music) facts for kids
Harmonics are special notes in music. They are like hidden notes that make up the sound we hear. When you play a musical instrument, you hear one main note. But actually, many other quieter notes are vibrating at the same time. These extra notes are called harmonics.
In physics, a harmonic is a wave that joins with a main, basic wave. For sound, these waves help us tell the difference between instruments. For example, a violin and a clarinet playing the same note sound different. This is because of their unique mix of harmonics.
When a violinist plays a note, the string vibrates very fast. This vibration makes the air vibrate, sending sound waves to our ear. The main note is called the "fundamental" or "first harmonic." But the string also vibrates in other ways, creating many other harmonics. These all combine to make the sound of the violin.
The higher the note, the faster the string vibrates. For example, an A string on a violin vibrates 440 times per second (440Hz). This is the fundamental. The second harmonic vibrates twice as fast (880Hz), which is an octave higher. The third harmonic vibrates at a 3:2 ratio, creating an E note. Higher harmonics are usually quieter. The important thing is that the ratio for harmonics is always a whole number.
Every note we hear is a mix of several notes or harmonics. We might not even realize we are hearing more than one note. You can try this on a piano:
- Play the lowest C note loudly and quickly.
- Now, find the next C note (an octave higher).
- Press this key very slowly so it does not make a sound, and hold it down.
- While holding it, play the low C again, loud and short.
- The C you are holding silently will now sound! This happens because its strings vibrate a little. They are responding to the low C, which is a harmonic of the low C.
You can do the same with the G note above that C, then the next C, and then the E. The higher the note, the quieter the harmonics become.
You can hear the notes of a harmonic series by clicking here.
Playing Harmonics on Instruments
Musicians sometimes play harmonics on purpose. In written music, a small circle above a note shows that it should be played as a harmonic.
Harmonics on String Instruments
A violinist can play a harmonic by lightly touching a string. If they touch it exactly in the middle, the string divides in half. This makes a harmonic that is an octave higher than the open string. By touching the string at other points, like a quarter of the way down, they can get different harmonics.
Artificial harmonics are harder to play. A violinist stops a string with one finger, making it shorter. Then, they lightly touch the string farther up with another finger. This creates a harmonic of the shortened note. These are written with diamond-shaped note heads in music.
Harpists can also play harmonics. They use their left hand to stop the string lightly with the side of their hand. Then, they pluck the string with their thumb or another finger. They can play up to three harmonic notes with their left hand. With their right hand, they stop the string with the upper knuckle of their second finger and pluck with their thumb. Only one harmonic note can be played this way. Harmonics on the harp sound very beautiful and airy.
Harmonics on Wind Instruments
Players of woodwind and brass instruments use harmonics to play many notes. They do this by blowing a bit stronger, which is called "overblowing." This makes a higher series of notes sound.
Some instruments, like the recorder, can even play chords by making several harmonics sound together. However, this is very difficult and is usually only done in modern music by expert players.
