instrument type plays four sounds demonstrating, in turn, each of the four types of instrument listed in the instrument type table:
Two aah sounds simulating the sound of the human voice.
Two chords on a guitar demonstrating the sound of a musical instrument.
A rhythm pattern on a snare drum demonstrating the sound of a percussion instrument.
A helicopter sound generated with a computer.
The instrument type figure shows the score for the first three instruments. The fourth instrument, the computer-generated helicopter sound, is not shown as it is better notated in a waveform or a spectrogram.
Voice means human voice. The solo human voice is an excellent melody instrument. With not too much effort it can also produce noise and rhythm. A single voice cannot generate harmony, for that you need a vocal group.
A musical instrument is what many people think of as an instrument. Every musical instrument can generate melody and many can produce noise and rhythm too. An instrumental group generates harmony. There is a small, select band of musical instruments that generates both melody and harmony. It includes the piano, keyboards and guitar, which is why these instruments are such popular choices for writing music.
A percussion instrument includes drums and cymbals and anything else that can be bashed. Percussion is excellent for rhythm of course. All percussion instruments can make noise too. Some percussion instruments can generate melody and a select few can generate harmony.
The computer is treated as an instrument in its own right. A computer is the most versatile of instruments. It can generate noise, rhythm, melody and harmony.
The Hornbostel-Sachs system is another method for classifying instruments. It covers percussion and musical instruments and slots them into one of five groups according to which part of the instrument vibrates:
Idiophone: the whole instrument vibrates, for example, a cymbal.