There are three common hymns of praise that typically follow after the Collect for Purity: the Gloria, the Kyrie or the Trisagion.
The Gloria is always used during Christmas and Easter seasons, and has its basis in the angels’ hymn of praise in Luke 2:14. It is never used during Lent.
The Kyrie is an ancient form of prayer, modeled after the prayer in Luke 18:9-14. It is often used during Lent as an alternative to the Gloria. This may be sung in English or in the original Greek (as heard below).
The Trisagion is used as an entrance hymn in Eastern Orthodox churches and is sometimes used as an alternative to the Kyrie.