Darius was born in Islington, London in 1966. His mother is from Lancashire and his father from a Parsee family in Bombay. He began to play the piano by ear at a very early age, later taking up the cello and finally the organ, becoming organist at St Mary, Islington when he was 13. He was educated at William Ellis School in Highgate, and later went to Leeds University to study music. After graduating with first-class honours he completed his studies with postgraduate diplomas in organ (with distinction) and piano accompaniment from the Royal Northern College of Music, where he won prizes on both instruments, including the Brigitte Fassbaender award for best lieder accompanist. His teachers included Ryzard Bakst, Martin Roscoe, John Wilson, Graham Barber and Ronald Frost. He also completed a MusM in performance at Manchester University.

Darius lives in Hebden Bridge, Yorkshire, with his partner Hannah and their three children.