Der Geist hilft unser Schwacheit auf, BWV 226 ("The Spirit Helpeth Our Infirmities") is one of five motets firmly ascribed to Bach. The small number compared with the composer's substantial output of cantatas may be accounted for by the fact that he was under no obligation to provide motets for liturgical use. The present work is in fact the only motet composed by Bach for which a specific purpose is known. It was composed for the funeral service of Johann Heinrich Ernesti, the elderly rector of the Thomasschule in Leipzig; the funeral took place on October 20, 1729. Bach had enjoyed good relations with Ernesti, who was 70 by the time Bach took up his post at the Thomasschule in 1723, and composed one of his finest motets for the rector's funeral. The text is taken from Romans 8:26-27; Bach's setting is a continuous single movement divided into several sections. The unexpectedly animated opening chorus is scored for eight voices disposed as two four-part choirs, with the melodic line shared by the sopranos of each group. Mood and tempo change for the second section, a fugue in five parts. This gives way to a double fugue in four parts, with the two choirs combined. The motet is generally concluded with a four-part chorale harmonization of a stanza from Martin Luther's hymn "Komm, heiliger Geist," which, although composed by Bach, is not part of the original work; it might have been used later in the service. The survival of the original autograph parts shows that Bach included a continuo bass, with strings to double the first choir and winds the second. Instrumental doubling was not unusual in motets, although they are ostensibly an a cappella form. ~ Brian Robins, All Music Guide
