sentences:  For example, the Octoechos' kontakion for Sunday Orthros in echos tritos has the indication, that it should be sung to the melody of the above Christmas kontakion.Both kontakia have nearly the same number of syllables and accents within its verses, so the exact melody of the former is slightly adapted to the latter, its accents have to be sung with the given accentuation patterns.The printed book Octoechos with the Sunday cycles is often without any musical notation and the determination of a hymn's melody is indicated by the echos or glas according to the section within the book and its avtomelon, a melodic model defined by the melos of its mode.