IMPROVISATION - IT'S NATURE AND PRACTICE IN MUSIC by Derek Bailey. FREE U.S.POSTAGE on everything - Order on cart with charge card or call 262 552 4012 10-5 CST for a real live person. - copy
This second edition is a walcome expansion and reorganization of Bailey's seminal 1980 book originally titled Musical Improvisation. This is the most important book on improvisation that you're likely to meet.