John Barnett was an English composer and writer on music. He was the eldest son of a Prussian Jew named Bernhard Beer, who changed his surname on settling in England as a jeweller. According to some he was a cousin of the composer Giacomo Meyerbeer. Barnett was born at Bedford, and at the age of eleven sang at the Lyceum Theatre stage in London. His good voice led to his being given a musical education, and he soon began writing songs and lighter pieces for the stage.