Johann Sebastian Bach's Violin Concertos, BWV 1041–1043, and his six "Brandenburg Concertos" survive in their original instrumentation. His harpsichord concertos are mostly adaptations of concertos originally written for other solo instruments.
In his early career Bach transcribed concertos by other composers for solo organ (BWV 592–596) and for solo harpsichord (BWV 972–987). Bach's "Italian Concerto", composed in 1735, was one of his few works that he published during his life-time: it is an example of an unaccompanied concerto for two-manual harpsichord.
Early encounters with the concerto genre.
The earliest documentary traces of Bach's involvement with the concerto genre include:
Weimar concerto transcriptions.
Bach wrote most, if not all, of his concerto transcriptions for organ (BWV 592–596) and for harpsichord (BWV 972–987) from July 1713 to July 1714. Most of these transcriptions were based on concertos by Antonio Vivaldi. Other models for the transcriptions included concertos by Alessandro Marcello, Benedetto Marcello, Georg Philipp Telemann and Prince Johann Ernst of Saxe-Weimar.
Concerto form in other compositions.
"Sonate auf Concertenart".
The "Sonate auf Concertenart" (transl. sonata in the style of a concerto) format appears for example in Bach's organ sonatas.
In vocal compositions.
Apart from adaptations of movements of his earlier concertos into his cantatas, Bach also directly composed movements of his vocal works in the concerto form: for example the opening chorus of his cantata BWV 7 has been described as having the format of an Italian violin concerto movement. Another example is the opening choral movement of Bach's Magnificat, the form of which only becomes, in Spitta's words, "thoroughly intelligible" when analysed as a concerto form.
Harpsichord concertos.
Concerto for two harpsichords, BWV 1061a.
BWV 1061a, a concerto for two harpsichords without accompaniment, is Bach's original version of the Concerto for two harpsichords and strings, BWV 1061.
"Italian Concerto", BWV 971.
Bach's "Italian Concerto", BWV 971, was published in 1735, as first of two compositions included in "Clavier-Übung II".
Concerto as a vocal composition.
Bach rarely used the name "Cantata" to indicate a vocal composition. Instead, "Concerto", closer to names of cantata precursors such as geistliches Konzert (spiritual concerto) and Choralkonzert (chorale concerto), is the name he used most often to indicate those compositions which later became known as his cantatas.
Sinfonia in D major, BWV 1045.
BWV 1045, a movement in concerto form for violin and orchestra, is the opening of a cantata titled "Concerto" in Bach's autograph ("J J Concerto. à 4 Voci. 3 Trombe, Tamburi, 2 Hautb: Violino ConC. 2 Violini, Viola e Cont."). The music breaks off before the vocalists enter. In the "Bach-Werke-Verzeichnis" it appears as "Konzertsatz in D" (Concerto movement in D major), in the range of the orchestral concertos (BWV 1041–65).
Doubtful and spurious.
For organ:
For harpsichord:
For chamber ensemble:
Orchestral concertos:
Reconstructions.
Detailed accounts of possible or conjectural reconstructions of Bach's harpsichord concertos for other solo instruments have been described systematically in the hand-book of Siegbert Rampe. No discussion for reconstructions is needed concerning the well-known two violin concertos BWV 1041, BWV 1042 and the double violin concerto BWV 1043, since these predate the harpsichord versions, BWV 1058, BWV 1054 and BWV 1062 respectively. The concerto BWV 1057 for harpsichord and two flutes or recorders also has an extant original: the 4th "Brandenburg Concerto", BWV 1049. The concerto for two unaccompanied harpsichords BWV 1061a was modified slightly by adding strings in the first and last movements to produce BWV 1061. Vivaldi's concerto for four violins Op. 3 No. 10 was reworked by Bach as his concerto for four harpsichords BWV 1065.
The 5th "Brandenburg Concerto", BWV 1050, always was a concerto for flute, violin and harpsichord, also in its earlier version BWV 1050a. Earlier versions for unaccompanied keyboard instruments of all three movements of the "Triple Concerto", BWV 1044, are extant. Other harpsichord concertos, and related cantata movements if available, have been the basis for several reconstructions. The letter "R", abbreviation of "Reconstruction", can be added to the BWV number of an extant Bach concerto to indicate a conjectured original of such concerto.
BWV 1052R.
Based on BWV 1052, 1052a and/or on cantata movements BWV 146/1 (Sinfonia) and /2 (Chorus), and/or on what is known regarding the lost opening Sinfonia of BWV 188 (a variant of the third movement of BWV 1052 scored for oboe, strings and obligato organ):
BWV 1053R.
Based on BWV 1053 and/or cantata movements BWV 169/1 (Sinfonia), /5 (Aria) and 49/1 (Sinfonia):
BWV 1055R.
Based on BWV 1055:
BWV 1056R.
Based on BWV 1056 and/or (for the middle movement) BWV 156/1 (Sinfonia):
BWV 1059R.
Based on the BWV 1059 fragment and on cantata movements BWV 35/1 (Sinfonia of Part I), 156/1 (Sinfonia) or 35/2 (Aria), and 35/5 (Sinfonia of Part II):
BWV 1060R.
Based on BWV 1060:
BWV 1063R.
Based on BWV 1063:
BWV 1064R.
Based on BWV 1064: