By 1759 John Valentine owned and operated a music shop on New Bond Street in Leicester, which he later moved to other locations.
John's son Thomas Valentine (1759 – c. 1800) was also a violinist, who performed in the Handel Commemoration and in the London area for at least a decade.
John's uncle, Henry Valentine, played oboe and also operated a music shop in Leicester.
Sarah (1771–1843) served as an organist at St Martin's Church in Leicester from 1800 to 1840, and composed at least one work, The British March and Quickstep for the Pianoforte.
Selected works include: Free scores by John Valentine in the Choral Public Domain Library (ChoralWiki)