She was born Joyce Amy Black in Hampstead, London in 1907.
Together with her husband, Finzi played an important part in founding the Newbury String Players.
She sketched portraits of contemporary musicians including Ralph Vaughan Williams, Sir Adrian Boult, Howard Ferguson and Sir Arthur Bliss, and writers including Edmund Blunden, Ursula K. Le Guin, Sylvia Townsend Warner and David Jones.
[2] In 1969, she founded the Finzi Trust to finance the recording of her husband Gerald's work and that of other composers, and was instrumental in the formation of Finzi Friends in 1982, a society furthering the work of the Trust.
She continued to draw and sculpt, and published two volumes of poetry: A Point of Departure and Twelve Months of a Year.