His father, Jenkyn Jones, was a composer and his mother a singer,[1] and by the time he was nine years old the young Daniel had himself written several piano sonatas.

At this period Jones and Thomas were part of the informal group of aspiring artists who would meet at the Kardomah cafe in Castle Street, Swansea.

[2] In the years leading up to the Second World War he composed his first large-scale orchestral works, Symphonic Prologue and Five Pieces for Orchestra, and developed his own compositional system of 'Complex Metres'.

During the war, as a captain in the Intelligence Corps (1940–1946), he used his linguistic abilities at Bletchley Park codes centre as a cryptographer and a decoder of Russian, Romanian and Japanese texts.

By 1993 he had composed eight string quartets, as well as works in many other genres, including the cantata, The Country Beyond the Stars, a setting of Henry Vaughan's poem.

Jones enjoyed long friendships with several artists, among them Vernon Watkins, Ceri Richards and Grace Williams, and, most closely, Dylan Thomas.