This documentary about the hugely prolific Frank Zappa, directed by Alex “Bill Preston Esq” Winter, takes an unusually serious-minded approach to the celebrated wild man of 1960s and 70s American rock: ranging from his unusual childhood, to his ferocious work ethic, to his political-sphere interventions, this is a fruitful attempt to get under the skin of a figure who is renowned for lurking eccentrically at the music industry’s periphery. One thing it doesn’t focus much on is the music itself; perhaps the ongoing devotion of Zappa’s hardcore fans means there’s no compelling reason to introduce the work to a new generation.