).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 introduce new material in the supposedly "ritornellic" sections, such as in K. 459, 488, and 491, or, indeed, in the middle section (K. 453, 459, and 488).