Bach Cantata BWV 115 has a very unusual shape. Two gigantic slow arias follow a brief, very quick choral scherzo. The opening movement has some of the fastest music in all of Bach. Certainly the operative word here is "Geist," meaning "spirit." The flute, oboe d'amore and unison strings dance around the chorale tune like vapors. In between the running scales and octave leaps is a surprising amount of chromatic writing that gives the movement an evanescent and elusive quality. After this mysterious groundless movement the heavy alto aria with its long oppressive pedal points in the bass seems earthbound, even imprisoned. The oboe d'amore at first doubles the first violins but finally breaks free to sings its arching mournful melody. The quick middle section is over so fast that one wonders if it ever existed. After a brief bass recitative, the great soprano aria is a gossamer web of sound. The flute and piccolo cello weave their transparent lines over which the soprano sings her poignant text. Much is made by Bach of the similarity between the word "Bete" (praying) and the word "bitte" (pleading). This is one of Bach's greatest and most profound arias. A four-voice harmonization of the opening chorale ends the work.