This “Prelude” explains the difference between the key terms, stage prologues and theatrical presentations, and then raises a series of questions that the book will address. It argues that, within the variety format of American movie theater programs, stage prologues played a significant, little-known role in introducing the feature films. It highlights the invaluable trade press photographs of prologue stage settings as well as their limitations for analysis. And it sketches the book’s organization into five chapters and an epilogue.