Different kinds of sounds

Frequency of vibration and pitch:

Large objects, like one of the strings of a double bass, vibrate slowly when plucked. Its frequency of vibration is low and only a small number of sound waves are produced each second. The note produced by the string will have a low pitch.
It is possible for you to see a picture that represents these waves using a piece of apparatus called a cathode ray oscilloscope (CRO).
Small objects, like a violin string, vibrate more quickly when plucked. Its frequency of vibration is higher so more sound waves are produced each second. The note produced by this string will have a higher pitch.
The frequency of an object or wave is the number of complete vibrations it performs each second. It is measured in hertz (Hz) where 1 Hz is one vibration per second.

Musical instruments:

Like all musical instruments, the double bass and the violin can produce notes with a wide range of frequencies and pitch. The changes in frequency produced by the vibrating strings are achieved by altering.
• The length of the string by changing the positions of the fingers on the frets board. The longer the vibrating string, the lower the pitch of the note produced.
• The thickness of the string. The thicker the string, the lower the pitch of the note produced.
• The tension of the string. The greater the tension, the higher the pitch of the note produced by the string.

Changes in the frequencies of the notes produced by wind instruments are achieved by altering the lengths of vibrating air columns.