 Apart from indicating his first published keyboard composition as Opus 1, Bach didn't use opus numbers, so Bach's works can't be listed by opus number.Lists following publication chronologies are for example implied in the first list in Bach's obituary, and BG numbers (within the BGA sequence of publication) – overall lists covering all of Bach's compositions in order of first publication are however not a way Bach's compositions are usually presented.Listing Bach's works according to their time of composition can't be done comprehensively