John Farmer was born in Nottingham on 16 August 1835, the eldest child of John Farmer and Mary Blackshaw, who were married at St Nicholas's Church, Nottingham on 10 November 1834.
At the time of the 1841 census John (5) was living in Nottingham at St James Street with his parents and his sisters Mary (4), Sarah Ann (2), and Catherine (11 months). His father was then a butcher and his mother a milliner, and they had two servants.
Farmer came from a very musical family, and learned to play the piano, violin, and harp when young. He was apprenticed to his uncle Henry Farmer, an organist, composer, and music teacher who had a music and musical instrument business in Nottingham. At the age of 14 he was sent to be taught at the Leipzig Conservatory, and then after three years he studied under Andreas Spaeth in Coburg for a year.
His mother’s millinery business must have been successful, because by 1851 his father was no longer a butcher but was described as a wholesale milliner. The census in the spring of that year shows the family living at Long Row, Nottingham. John (15), who was at home in England on census night, was described as a musician, and he now had two additional younger siblings: William (8) and Thomas (7). Three female assistants and a male apprentice also lived in the house, plus a cook and general servant.
In 1853 Farmer returned to live in England and took a job in the London branch of his father’s lace business. Following his mother’s death in 1856, he went to Zürich, and supported himself by music teaching.