In the case of Johan Sebastian Bach, the practice of musical transcription can be considered, an audacious act or an act of will, depending on the perspective from which it is observed. It is an audacity in relation to the level of boldness necessary to confront such a challenge, and an act of will in relation to an aspiration that risks to be unsustainable, because of the high level of difficulty of the task. The musical form of instrumental concerto occupied a role of primary importance in the evolution and the definition of the style and language of the German musician. Such form encountered extreme fortune and growing importance starting from the end of the XVII century until the end of the XVIII century. He was certainly not the first musician to confront himself with this genre; indeed, it is possible to state that the activity of musical transcription characterized the first productions of keyboard music, and accompanied it constantly from its origins to our day, As it is well known, the transcriptions of concertos composed by Italian musicians were made by Bach in 1713/14 on a prompting by young Prince Johann Ernst of Saxony–Weimar (1696-1715), the nephew of Duke Wilhelm Ernst. Moreover, during that period Bach had occasions to wor