One of Bach's most famous church cantatas, BWV 140[1], was written for the 27th (or no. 3^3, the importance of this will be apparent in a moment) Sunday after T

One of Bach's most famous church cantatas, BWV 140[1], was written for the 27th (or no. 3^3, the importance of this will be apparent in a moment) Sunday after Trinity, the last possible Sunday before Advent. The cantata is a chorale cantata based on the Lutheran Hymn "Wachet auf, ruft uns die Stimme", the opening movement is a chorus that is based on this tune. The tune is in Bar form, the first 3 verses are repeated, followed by 6 verse which is sung once through (3x2 + 3x2), and Bach's chorus mirrors this structure. Bach decided to set the piece in E-flat, which is a key signature with 3 flats. He also decided to make the time signature 3/4, so each bar has 3 beats. There are 3 groups of musicians involved (not counting the obligatory basso continuo): 1) vocal forces, 3 parts (Soprano + Alto + Tenor, the bass mostly doubles the basso continuo and is not independent); 2) strings, 3 parts (violin 1 + violin 2 + viola); 3) winds, 3 parts (oboe 1 + oboe 2 + alto oboe). Also, the opening melody of the chorale outlines the 3 notes of the tonic triad of E-flat (E-flat, G, B-flat), while later on, Bach being Bach, there is a miniature fugato where the three lower voices open with the same 3 pitches in a different order (G, B-flat, E-flat). I'm usual sceptical of most other numerological readings of Bach's music precisely because when Bach wished to make a point with numbers, he makes it damned obvious, as in this case. [1] https://www.youtube.com/watch?v=WfNeJ-Cedeo https://www.youtube.com/watch?v=WfNeJ-Cedeo