Sounds to the air around us, some are harsh, others pleasant even melodic. Some send warning signals to others. Imitation of these sounds was probably the first musical expression. The most fundamental instruments and the most portable is the human voice. It can imitate bird song or vocalizing in Coral Harmony. The voice as an instrument can be reached at its peak in operatic duets.

Rhythmic vocal chanting can be reinforced with a drum. Percussion instruments come in many forms from naturally toned producing objects like woodblocks, gongs and metal sheets. The drums are made from stretched tyres and modernity synthetic membrane.

Song is produced by blowing air across the vocal chords and shaping a sound in the mouth and throat. The same principle makes musical sounds in hollowed cubes and pipes. The simplest and most taunting wind instruments are the South American Indian flute. The most enlightening comes from the brass section of a modern marching band.

Another type of musical sound can be created by plucking a stretched string. The ancient lyre and harp are early forms of plucked instruments. The contemporary piano is a variation of the harp. Single rhythms on the guitar and playing stories of daily life formed the basis for the popularity of folk songs and country and western music.

Ragas played on the Indian sitar are renowned for the intricacy of their rhythmic patterns. Wood strings produce long smooth sounds. Many cultures have developed this type of instrument. The violin family and stringed instruments was developed in Europe. Variations in instrument size reproduce the pitch ranges of the human singing voice. Quartets like composers like Beethoven harmonized the four different ranges of extreme sounds.

The string section forms the major musical sound of a modern symphony orchestra. Other sounds are created by woodwinds, brass and percussion. The invention of musical notation in Europe has helped to establish the names and preserve the exact musical scores of both classical and contemporary composers.

Electricity has had a profound influence on 20th century music. Amplifiers have changed the role of many instruments particularly the guitar. Techniques of sound recording have brought high quality music into the home from all over the world.

Since the 1960s, the use of digital computers has opened up a new era in music. An electronic synthesizer can create any sound imaginable. It can generate the human voicing song, a single violin or orchestra, or previously unheard sound combinations. Composers are now venturing all into completely new and unique musical terrain.