U+1D0B3 "𝂳" Byzantine Musical Symbol Martyria Plagios Tetartos Ichos Unicode Character

U+1D0B3 "𝂳" Byzantine Musical Symbol Martyria Plagios Tetartos Ichos is a specialized sign from the Byzantine musical notation system, used in the Eastern Orthodox liturgical tradition to denote the plagios tetartos (or fourth plagal) mode, which is a specific scale pattern within the Octoechos, the eight-mode system of Byzantine chant. This symbol, known as a martyria, functions as a modal signature or key indicator, instructing the chanter on the tonal center and melodic framework for the piece that follows. Its inclusion in the Unicode standard helps preserve and digitally represent this ancient form of neumatic notation, ensuring accurate reproduction of historical liturgical manuscripts and modern scholarly editions.