An introduction to the skill of musick, [electronic resource] : in two books the first contains, I. The grounds and rules of musick according to the gamūt, and other principles thereof the second, instructions and lessons for the basse-viol, and treble-violin / by John Playford ; to which is added, the Art of descant, or composing of musick in parts by Dr. Tho. Campion, with annotations thereon, by Mr. Chr. Simpson ; also The order of singing divine service in cathedrals.