During his long and creative career, Carl Philipp Emanuel Bach (1714 –1788) composed more than 50 concertos for one soloinstrument and orchestra. Although the majority of his concertos are destined for keyboard, approximately one dozen concertos were originally written for flute, oboe, or cello and were only later adapted to C. P. E. Bach’s own instrument, the harpsichord. Between 1750 and 1753, Bach wrote cello concertos in A minor (Wq 170), B flat major (Wq 171) and A major (Wq 172); at the same time his half-brother Johann Christian, who lived in his household after their father’s death, composed a now lost cello concerto as well. These works belong to the earliest concertos for this solo instrument in Germany. It is not known whether the concertos were written for the violoncellist Ignaz Mara (1721– 1783), who was, like Bach, a member of the Prussian court orchestra, or for another virtuoso.
According to the Verzeichniß des musikalischen Nachlasses des verstorbenen Capellmeisters Carl Philipp Emanuel Bach (“Catalogue of the Musical Estate of the Late Capellmeister Carl Philipp Emanuel Bach”), Hamburg, Schniebes, 1790, p. 31, no. 29, the present concerto in B flat major Wq 171 was composed in Potsdam in 1753 and exists also in two further authentic versions – for flute (Wq 167) and for harpsichord (Wq 28).
The autograph score is not known to survive. The texture of the solo and basso continuo parts leaves no doubt that the work was conceived with a melody instrument in mind, not a solo harpsichord. There exists an authentic cadenza for the slow movement in manuscript 5871 MSM of the Royal Conservatory in Brussels with the heading “Cadenz zum Adagio des Violonc. Conc. aus dem B. No. 29.” which suggests that the cello version was the original scoring. The concerto was disseminated in several copies in the second half of the eighteenth century. The most trustworthy is a fair copy from the mid-1790s by Bach’s main scribe Johann Heinrich Michel for the Schwerin collector Johann Jakob Heinrich Westphal (today in the library of the Royal Conservatory in Brussels, shelf number 5633 MSM) which is based on lost sources from Bach’s personal library. From a letter written by the Hamburg music dealer Johann Christoph Westphal to the Schwerin Westphal it is known that the former had acquired a copy of this concerto with autograph annotations from a dilettante who had ordered copies from Bach but was unable to play the demanding concerto. This source is lost, but a manuscript sales copy of it is preserved in the collection of Patrick Alströmer (1733–1804) housed since 1949 in the Statens Musikbibliotek Stockholm. A third contemporary copy of the concerto is found in the collection of the Sing-Akademie zu Berlin (on deposit in the Staatsbibliothek zu Berlin – Preußischer Kulturbesitz, shelf number SA 2592); this manuscript is, however, of uncertain origin and was prepared less carefully than the other manuscripts.
In all surviving sources the cello solo part includes the orchestral ritornellos. We may therefore assume that the soloist was meant to lead the performance and it is left to the modern performer to which extent he wishes to participate in the ritornellos and the orchestral interjections which divide the solo episodes. The eighteenth-century sets of orchestral parts contain an extra part for double bass that drops out with the violins and the viola during certain solo episodes. By kind permission the edition is based on the posthumous set of parts from the collection of Johann Jakob Heinrich Westphal (Royal Conservatory in Brussels), the Stockholm manuscript was used for comparison.

Salzburg, Spring 2006