1 Aims of Creating musical sounds
The aims of this unit are to:
introduce the idea that a musical instrument is made up of several component parts and that each component has natural frequencies at which it prefers to vibrate;
introduce the concept of standing waves and explain how a standing wave is made up of two travelling waves;
show that a component prefers to vibrate at its natural frequencies because these are the frequencies at which standing waves can be set up within the component;
explain that, when a note is played, a musical instrument vibrates strongly at the natural frequencies of the dominant component (the primary vibrator);
calculate the natural frequencies of the primary vibrators of string, wind and percussion instruments and describe the corresponding standing-wave patterns;
show that pitched instruments tend to have primary vibrators with harmonically related natural frequencies while unpitched instruments tend to have primary vibrators that do not have harmonically related natural frequencies;
explain how the other components of an instrument (the secondary vibrators) are often responsible for improving the radiation of sound from the instrument.