Any musical sound can be described in terms of four qualities or elements.

Pitch
Pitch is the location of a tone in the musical scale in relation to high or low. The pitch is determined by the rate of vibration. This mainly depends on the lenght of what is being vibrated. All things being equal (ceteris paribus), the shorter a column of air or the short the string the more rapidly it vibrates and the higher the pitch. Conversely, fewer vibrations per second are due to a longer column of air or a longer string producing less vibrations and hence a lower pitch.

Duration
Duration depends on the length of time over which the vibration is maintained. Tones are perceived as being long and short as well as high or low.

Volume
Volume, or dynamics, is dependent upon the degree of force of the vibrations. The result of volume is the perceiving of tones to be either loud or soft.

Timbre
Timbre is the tone color of sound. This element of sound is what distinguishes the sounds of musical instruments from one another. Timbre is influenced by the size, shape and proportions of the instruments and the material of which it is made and the manner in which the vibration is set up.