Entirely apart from its complexity, stands the fact that Bach’s musical structure is most expressive, and even if the hearer loses a word here and there, he cannot fail to catch the spirit, especially in such passages as the joyous _Gloria_ and the calm _Et in terra pax_. It is true that Bach’s works, in his own time as now, required a somewhat trained listener, but his themes are so characteristic of the verbal ideas expressed in the text that they are in themselves an eloquent, yet simple, commentary on it. The _Kyrie_ alone consists of three elaborate parts, the first of which ends in a five-part fugal chorus. The second part, _Christe eleison_, is a duet sung by two sopranos. It has a simple, childlike quality of entreaty and is followed by the third part, _Kyrie eleison_, again fugally treated in four parts. The following number, the _Gloria_, which, with the _Credo_, stands at the summit of choral-writing, consists of eight musically complete parts, the last of which, _Cum sancto spiritu_, written for five-part chorus, is one of the most powerful and exalted of the entire work. The _Credo_ is set on the same vast lines as the _Gloria_. Beginning with a theme taken from a Gregorian chorale, the composer develops it fugally after it has been announced by tenors, basses and altos. The _Credo_ also consists of eight parts, the choral first part being followed by a most elaborate soprano and alto duet (_Et in unum Dominum_), after which follows the five-part fugal chorus (_Et incarnatus_). The _Crucifixus_ is one of the most remarkable portions of the entire work. The bass theme, appearing thirteen times in succession, gives a remarkable background, and with the other choral parts, which move freely over it, creates an atmosphere of mingled pain, sorrow and consecration. _Et resurrexit_ is taken up by the five-part fugal chorus, which is full of joy. _Et in spiritum sanctum_ is a bass aria introduced by the oboe d’amour and the _Confiteor unum baptisma_ closes this group with an intricate five-part double fugue. The _Sanctus_ is a massive six-part chorus, the _Osanna_ is an eight-part chorus, the _Benedictus_ is a tenor solo with violin obbligato, and the _Agnus Dei_ an alto solo. The last chorus (_Dona nobis pacem_) is in four parts and this brings this monumental work to a close. Its great difficulty has militated against its being as frequently performed as it certainly merits. Complete performances of it have been given at intervals since its complete production at the Berlin Singakademie in 1835. Its first performance in America was the one given at Bethlehem, Pennsylvania, in 1900, at the Bach Festival under direction of J. Frederick Wolle. IV