This layered chant commonly used for the service of Compline was written by tunesmith Ana Hernández. Here's a description of the piece from her website:
Guide Us Waking, Guard Us Sleeping is an eight-part circular chant with optional piano accompaniment you may improvise in almost any musical style, from early music to gospel. It's also beautiful with unaccompanied voices. You may also use as few as three parts and still create something beautiful, which makes it perfect as an anthem for small choirs, chanting groups, and improvisors. My friend Julia taught it to her choir and they sang it at the end of rehearsal every Thursday night for years while they put away their books and put on their coats.
"Guide us waking, guard us sleeping,
that awake we walk in love/watch with Christ;
and asleep we may rest in peace."