In this concerto for harpsichord, flute and violin, occasionally referred to as Bach's "triple concerto", the harpsichord has the most prominent role and greatest quantity of material. Except for an additional ripieno violin part, the instrumentation in all three movements is identical to that of Brandenburg Concerto No.5 in D major, BWV 1050. Arranged from previous compositions, the concerto is generally considered to date from the period 1729–1741 when Bach was director of the Collegium Musicum in Leipzig and was responsible for mounting weekly concerts of chamber and orchestral music in the Café Zimmermann. and contain a comprehensive discussion of the concerto, including its history and questions of authenticity. Because one of the earliest surviving manuscripts comes from the library of Frederick the Great and because of post-baroque galant aspects of the instrumental writing—fine gradations in the dynamical markings ("pp, p, mp, mf, f"), the wider range of the harpsichord part as well as frequent changes between pizzicato and "arco" in the strings—Wollny has suggested that the arrangement as a concerto might have been intended for Frederick, a keen flautist who employed Bach's son Carl Philipp Emanuel as court harpsichordist; this could imply a later date of composition. Some commentators have questioned the authenticity of the work, although it is now generally accepted.