Rorate Coeli for unaccompanied chorus, was written in 1973 in response to a commission from the National Federation of Music Societies in Great Britain. It was first performed by the Thomas Tallis choir in Greenwich. It is a setting of two interleaved poems of the famous Scottish poet William Dunbar (written circa 1500). One poem is the Nativity poem of the title, the other is the poem about the Resurrection: Done is a battle on the dragon black. The work is framed by the rich chords of the opening line where full chorus is echoed by soloists. This setting of both poems simultaneously, reminiscent of medieval polytextural techniques, shows the future victory of the Resurrection along with the present joy of the Nativity. The chords of the opening return at the end combined with an exultant Gloria.