Chichester Psalms was written in 1965 by Leonard Bernstein, who also wrote West Side Story (see our previous post on Mambo). You can hear the same infectious rhythms in this piece once the fast section starts around 0:42. It’s quite difficult to sing as the harmonies are difficult and the choir parts have a very wide range.
Leonard Bernstein (1918-1990) was a colourful character who led an extremely interesting life as a composer, conductor, pianist, author, and lecturer. Here is a great pic of him (we don’t condone smoking, but it’s great to see a ‘serious’ musician playing a kazoo!):