In the year 1969 the rock press began circulating a rumor (or was it fact?) that budding rock genius Frank Zappa was planning a twelve-album box set (or was it five albums?- or nine?- or ten?) of unreleased live recordings (or was it studio?), to be titled The History and Collected Improvisations of The Mothers of Invention. Unreleased recordings by important rock artists often achieve iconic status; consider the Beatles' Get Back, the Beach Boys' Smile, or Jimi Hendrix's First Rays of the New Rising Sun. In each of these cases, public demand eventually led to the release of a post-hoc version of the lost work: for the Beatles, Let It Be...Naked; for the Beach Boys, Brian Wilson's SMiLE; for Hendrix, the MCA First Rays compilation. Zappa's History set has been every bit as sought after as these other titles - but has never seen the light of day. Or has it? In this book, authors Philip Lee and Scott Parker delve into the history of this unreleased Holy Grail of unreleased Frank Zappa projects.