Jack Mullin’s influence extends from the creation of tape following World War II to the rise of the iPod in recent times. Sound Man sheds welcome light on the career of this neglected pioneer, responsible for the innovation described as “a musician’s dream.” A Bay Area engineer turned WWII soldier, Mullin came upon a certain recording machine during his expeditions in Europe. The contraption, known as magnetophone, was to become the linchpin for the U.S. recording industry, allowing the voices of Bing Crosby and Les Paul, among others, to be saved for future generations. From then on, it’s only a step to the shift from records to tapes and the growth of Ampex, one of the early titans of the Silicon Valley. Having helped revolutionize the entertainment world, Mullin, quietly living with his family, was happy to stay out of the spotlight. Sound Man’s subtitle, “From WWII to MP3,” indicates the important contributions of this fascinating personality, finally given deserved tribute. Director Don Hardy has assembled a vast array of interviews (including musicians Les Paul, Greg Kihn, Chuck D., and Stephen Stills, Bing Crosby’s widow Kathryn, Mullin’s friends and family) to bring us the story of this essential player in the music industry, a true “sound man.”