Keyboard concertos by Johann Sebastian Bach practice that lasted until the early nineteenth century, namely the soloist played along with the orchestra in "tutti" sections, only coming into prominence in "solo" passages. The works BWV 1052–1057 were intended as a set of six, shown in the manuscript in Bach's traditional manner beginning with 'J.J.' ("Jesu juva", "Jesus, help") and ending with 'Finis. S. D. Gl.' ("Soli Deo Gloria"). Aside from the Brandenburg concertos, it is the only such collection of concertos in Bach's oeuvre, and it is the only set of concertos from his Leipzig years. The concerto BWV 1058 and fragment BWV 1059 are at
Piano concertos by Wolfgang Amadeus Mozart orchestra" rather than the more obviously "piano" concertos of the nineteenth century (e.g., that of Grieg etc.). Because Mozart was developing the form of his concertos as he wrote them and not following any preconceived "rules" (apart, presumably, from his own judgement of taste), many of the concertos contravene one or other of the generalisations given above. For example, K. 488 in A major lacks new expositional material, and "merely" repeats the preludial material; further, it effectively merges the first ritornello and the middle section, as does K. 449 in E. Several of the later concertos do not hesitate to