Switched-On Brandenburgs, and Switched-On Bach 2000) have second movements that are completely different from each other. Occasionally, the third movement from Bach's Sonata for Violin and Continuo in G, BWV 1021 (marked Largo) is substituted for the second movement as it contains an identical 'Phrygian cadence' as the closing chords. The Largo from the Sonata for Violin and Obbligato Harpsichord in G major, BWV 1019, has also been used. The outer movements use the ritornello form found in many instrumental and vocal works of the time. The first movement can also be found in reworked form as the sinfonia of the cantata Ich liebe den Höchsten von ganzem Gemüte, BWV 174, with the addition of three oboes and two horns. This concerto is the shortest of the six. Concerto No. 4 in G major, BWV 1049 Title on autograph score: Concerto 4to à Violino Principale, due Fiauti d'Echo, due Violini, una Viola è Violone in Ripieno, Violoncello è Continuo. Concertino: violin and two recorders (described in the original score as "flauti d'echo"). Ripieno: two violins, violas, violone, cellos and basso continuo (harpsichord and/or viola da gamba) Duration: about 15 minutes and 20 seconds The violin part in this concerto is extremely virtuosic in the first and third movements. In the second movement, the violin provides a bass when the concertino group plays unaccompanied. It has been debated what instrument Bach had in mind for the "fiauti d'echo" parts. Nowadays these are usually played on alto recorders, although transverse flutes are sometimes used instead: it is also theorised Bach's original intent may have been the flageolet. In some performances, such as those conducted by Nikolaus Harnoncourt, the two recorders are positioned offstage, thus giving an "echo" effect. Bach adapted the 4th Brandenburg concerto as a harpsichord concerto, BWV 1057. Concerto No. 5 in D major, BWV 1050 Title on autograph score: Concerto 5to à une Traversiere, une Violino principale, une Violino è una Viola in ripieno, Violoncello, Violone è Cembalo concertato. Concertino: harpsichord, violin, flute Ripieno: violin, viola, cello and violone Duration: about 23 minutes The harpsichord is both a concertino and a ripieno instrument. In the concertino passages the part is obbligato; in the ripieno passages it has a figured bass part and plays continuo. This concerto makes use of a popular chamber music ensemble of the time (flute, violin, and harpsichord), which Bach used on its own for the