His father, also named John was a butcher and his mother, Mary, was a milliner. The eldest of four children, Farmer was recognised as child prodigy, playing violin, piano and harp. His uncle Henry Farmer was also a conductor, composer, violinist and organist in Nottingham. He owned a successful music-warehouse and nurtured his nephew's musical talent. Between 1849 and 1852, Farmer studied piano at the Leipzig Conservatory with Ignaz Moscheles, after which he studied for a year in Coburg under Andreas Spaeth, a composer, organist and clarinetist. Farmer returned to England to briefly work in his parents' millinery business, then travelled to Switzerland in 1853, marrying Mary Elizabeth Stahel in 1859, the daughter of a Zurich schoolteacher, with whom he eventually had 7 children. His daughter Mary was married to the Scottish classicist John Burnet. Farmer suffered a stroke at Oxford in 1900 and died in July, 1901. He was buried at St Sepulchre's Cemetery, Oxford.
After teaching in Zurich for some years, John became music master and violin teacher at Harrow in 1862, reportedly appointed as a result of being noticed while giving piano demonstrations at the London International Exhibition. During his time at Harrow, he introduced 'house-singing' and composed many school songs and other larger vocal works for the education and enjoyment of students and staff. He encouraged the participation of the boys in massed singing for school events and the serious study of instrumental music. This was during a period when the inclusion of music within public schooleducation in England was in its infancy and its acceptance was often resisted by school boards and principals. Affectionately known as "Sweaty John", Farmer also introduced the smoking concert, or "Tobacco Parliament", that was held on Founder's Day, where school songs and musical contributions were welcomed from staff, boys and friends, with Farmer's items particularly memorable - he was remembered as a "capital entertainer" according to John Ivimey. His songs continue to be published in modern editions of the "" book. The school song, “Forty Years On”, was written in 1872 with fellow teacher Edward Ernest Bowen as lyricist. He also composed cricketing ditties like "Willow the King," one of the most famous of all cricketing songs. His opera, "Cinderella" was performed at Harrow in 1883. His pupils included Elsie Hall.
Farmer left Harrow in 1885 to take up the post of Organist at Balliol College, Oxford. During his tenure, he founded the Balliol College Musical Society. His proposed Sunday evening concerts in the College Hall were initially controversial when the performances on the Sabbath were strongly disapproved of by strict . However, the Sunday evening concerts are still presented by the College Music Society While at Balliol he composed Warwick School's first school song, Here's a Song For All, in 1892. He championed the music of Bach, editing two volumes for school students, and his own oratorio "Christ and His Soldiers" was popular with smaller choirs. Most of Farmer's stage works were intended for amateurs, often youngsters.
Compositions
Christ and His Soldiers - 1878 - a children's oratorio
