This introit was written in 1976 and revised in 2010. It is based on the traditional plainsong setting of the Kyrie from the Requiem Mass. It is written for unison choir, which may be all trebles, all male or mixed voices, plus organ. It last just over two and a half minutes.
The organ part develops the plainsong melody in trio form in counterpoint to the choir, which sings the original plainsong unmodified.