The passion is written in two parts, between which the sermon intervened in old times. It includes portions of chapters xxvi. and xxvii. of the Gospel according to Saint Matthew, the remainder of the text being composed of hymns furnished to Bach by Christian Friedrich Henrici, who wrote under the pseudonym of "Picander," and, it is said, was assisted in the compilation by the composer himself. The _dramatis personae_ are Jesus, Judas, Peter, Pilate, the Apostles, and the People, or _Turbae_, and the narrative is interpreted by reflections addressed to Jesus, forming two choruses, "The Daughter of Zion" and "The Faithful," as Picander calls them. They are sometimes given by the chorus, and sometimes by single voices. The chorales are selected from those which were in common use in the Lutheran Church, and were familiar therefore to the congregations which sang the melody, the harmony being sustained by the chorus and instruments. The Gospel text is in recitative form throughout, the part of the evangelist, or narrator, being assigned to a tenor voice, while those of the persons incidentally introduced are given to other singers. In the dialogue, wherever the words of Jesus occur, the accompaniment is furnished by a string quartette, which serves to distinguish them from the others, and invests them with a peculiar gentleness and grace. The incidental choruses, sung by the People and the Apostles, are short and vivacious in character, many of them being in madrigal form. The chorales, fifteen in number, as has already been said, were taken from the Lutheran service. One of them, which Bach also liberally used in his "Christmas Oratorio," beginning, "Acknowledge me, my Keeper," appears five times in the progress of the work, forming the keynote of the church sentiment, and differently harmonized on each occasion. Another, "O Blessed Jesus," is twice used,--once where the Saviour announces that he will be crucified after the Feast of the Passover, when the whole congregation sings it, and again in the scene at Gethsemane, sung by select choirs. The whole work is written for double chorus, the two choruses singing the harmony of the chorales, accompanied by the instruments, while the congregation sing the tune in unison. They display to the utmost the breadth, richness, ingenuity, and power of Bach in this form of writing. The reflective portions of the work, the text written by Picander, are composed of arias introduced by recitative, with the first part repeated in the close; of arias accompanied by chorus; and of single choruses constructed in the most massive manner. Speaking of the melodies in these portions of the work, Spitta says,--