Composers create music. Among the types of music they compose are classical jazz folk and pop. Most composers write their original musical compositions using musical notation which is essentially a set of strict instructions on how the piece should be played.
This notation is used by musicians who reproduce the piece for use in theatre and opera productions or for television film radio and so on. However musical performers often interpret the composer's written notation in their own unique way.
In recent decades the definition of composer has been expanded to include those who use electronic media to create music. This technique differs from instrumental composition in which there is a musical score to be followed by those who actually perform the piece. Some composers have no formal training and are self-taught but the majority of composers have taken music lessons from an early age. Eventually they attend a music school or conservatory where they study music theory composition orchestration and harmony.
It is essential for composers to be adept at playing at least one instrument and preferably several. This career is highly competitive and most composers will have to supplement their incomes by teaching music or playing in a symphony orchestra or band.
However the website Musiced.about.com states that a composer who is innovative creative versatile passionate about writing music and works hard at making job contacts can eventually earn a good income.
According to the website Careers.stateuniversity.com the median annual income for composers is approximately $35000.