Composed sometime between 1732 and 1735 for the Sixth Sunday after Trinity, Bach's Cantata No. 9 "Es ist das Heil uns kommen her" (Salvation has come to us) (BWV 9) is based on a hymn by Paul Speratus from 1523. The unknown poet who wrote Bach's text dropped the last two verses of Speratus' 14-verse poem, set the first and 12th verses as the first and seventh movements of the cantata, and re-worked the second through 11th verses as the central sequence of arias, duets, and recitatives. The cantata is scored for bass, tenor, soprano and alto soloists, chorus, solo transverse flute, oboe d'amore, strings, and basso continuo. The cantata is in E major, with its first and seventh movement in the tonic, its second starting in C sharp minor and ending in B major, its third in E minor, its fourth starting in B minor and ending in A major, its fifth in A major, and its sixth in B major. The first movement is typical of the opening movements of Bach's cantatas, with its orchestral polyphony interspersed with lines of Speratus' hymn stated in the sopranos and florid embellishments in the lower choral voices. The solo flute, oboe d'amore, and occasional concertante solo violin give the movement a brilliant, concerto-like texture. The second, fourth, and sixth movements are all dour recitatives for bass and basso continuo, but with the fourth closing with a two-bar arioso. The third movement is earnest da capo aria for tenor, orchestral violins, and continuo. The fifth movement is a da capo aria for soprano and alto duet accompanied by flute and oboe d'amore over a simple continuo. Interestingly, both the woodwind soloists and the singers develop the musical material as a series of canons. "Es ist das Heil uns kommen her" concludes with a lush harmonization of the final verse of Speratus' hymn for the entire chorus and orchestra. ~ All Music Guide
