Holy God [SATB]

The Trisagion ‘Thrice Holy', sometimes called by its opening line Agios O Theos, is a standard hymn of the Divine Liturgy in most Orthodox and Eastern Catholic churches.

The Trisagion is chanted immediately before the Prokeimenon (verse or passage) and the Epistle reading. It is also included in a set of prayers named for it, called the Trisagion Prayers, which forms part of numerous prayer services (the Hours, Vespers, Matins, and as part of the opening prayers for most Divine Liturgies).