Priaulx Rainier was born on 3 February 1903 at Howick, Natal, South Africa, of English-Huguenot parents. Her early childhood was spent in a remote part of the country near Zulu land, where the liquid language and music of the indigenous people, the sounds of wild animals and the calls of the birds were to prove a lasting influence.
As a violin student, at the age of ten, she entered the South African College of Music and, under the stimulating influence of the Principal, W. H. Bell, played a great deal of chamber music. In 1920 the University of South Africa Overseas Scholarship brought her to the Royal Academy of Music where she studied violin. Subsequently she settled permanently in London.
Necessity required her to earn her living as a violinist. Not until a grant was provided in 1935 was it possible for her to concentrate on composition. Between 1935 and 1939 Three Greek Epigrams and the String Quartet were written; a short period of study with Nadia Boulanger in Paris followed, before the outbreak of the 1939-45 War.
In 1943 Priaulx Rainier was appointed a Professor of Composition at the Royal Academy of Music, a post she held until 1961. In 1952 she was elected a Fellow of the Royal Academy of Music and Collard Fellow of the Worshipful Company of Musicians.
Her String Quartet was first played in London in 1944. It received several further performances in England and abroad, and subsequently at the Edinburgh Festival in 1949 by the Loewenguth Quartet of Paris. The Amadeus Quartet recorded the work for Decca in 1951 and it immediately encouraged further interest in her music. Doris Humphrey, pioneer choreographer with José Limon’s famous company from New York, used the Quartet for a ballet, Night Spell, included in their 1957 Sadler’s Wells season. A BBC Invitation Concert in 1967 presented four works, including the first performance of the String Trio and the Suite for solo cello. In 1976 the BBC recorded and broadcast the complete chamber music, including her largest chamber work The Bee Oracles.
Priaulx Rainier was much loved and respected by performing musicians for the finely calculated musical qualities of her work: she received commissions from many famous artists and developed a close association with the Menuhin School, whose pupils regularly play her chamber music. Her violin concerto, Due Canti e Finale, was commissioned by Yehudi Menuhin and performed by him at the 1977 Edinburgh Festival with the Royal Philharmonic Orchestra conducted by Sir Charles Groves and subsequently at the BBC Promenade Concerts, where it was received with warmth and enthusiasm. Concertante for Two Winds and Orchestra was written for and dedicated to Janet Craxton and Thea King and was premiered at the BBC Proms in 1981.
In June 1982 the University of Cape Town honoured her with a Doctorate in Music (Honoris Causa).
Priaulx Rainier died in France on 10 October 1986.