The Dream of Gerontius
There are three solo singers in the work.  The most important is the tenor soloist who sings the words spoken by the dying Gerontius.  There is also a bass who sings the Priest, and a mezzo-soprano who sings the part of the angel.  The Angel of the Agony can be sung by the same bass who sings the Priest.  The choir sometimes divides into two, and sometimes there is a small group of upper voices called the “semi-chorus”.