Song of the Watchmen of Modena

The Song of the Watchmen of Modena, also known by its incipit O tu qui servas, is an anonymous late ninth-century Latin lyric poem that encourages the guards who stood watch on the walls of Modena. Its musical notation has survived. The poem contains later interpolations and was probably composed for use at a Mass sending off the guards for duty. The poet invokes the blessing of Christ, the Virgin, and John, and cites the Trojan War and the Sacred Geese from classical history to encourage the guards.