An inspired improviser with an approach to the guitar both well-formulated and idiosyncratic, Joe Morris spent the last three decades refining creative ideas, playing in myriad instrumental situations, and earning what serves as fame on the free jazz scene. Now he’s written a book, Perpetual Frontier: The Properties of Free Music, which explains the quantifiable aspects of what’s oft-considered a mysterious music – “a methodology that can be used to construct a methodology,” says the bandleader and New England Conservatory teacher. The 27 gigs he’s curated at the Stone for the next two weeks will likely reveal the essence of the tome’s tenets. His current cohort stretches from Boston to Barcelona with a variety of characters uniting to make everything from doom skronk (Spanish Donkey) to chamber-prov (Ultra) to ye olde free-bop (Bass Quartet). Need an extended portrait of one man’s provocative vision? Here it is.