De Profundis was the first new composition written after Part's emigration, and belongs more with the Estonian tintinnabuli works, with their unwavering adherence to a simple unfolding of material in basic tintinnabuli manner, than to the relatively more intricate manner of the later Latin works. It is scored for male voices (TTBB), organ, and percussion (bass drum, E bell, and tam-tam) - the percussion is marked 'ad lib,' though much would be lost by its omission. The organ provides a relentless walking bass beneath alternate phrases, while the voices declaim the text in steady minim beats throughout. (Paul Hillier)