As with Salmon’s Essay to the advancement of musick, it seems that the appearance of his 1688 Proposal was preceded by a fairly lengthy period of work on the material which it contains. Salmon corresponded with John Wallis from 1685 – perhaps earlier – and by late 1685 had ‘rectifed’ his ‘Harmonicall Canon the third time’. Another two years would pass before his ideas about musical tuning were printed. The Introduction to Chapter 2 discusses the possibility that ‘The Use of the Musical Canon’ is evidence for Salmon’s work during that period.