A middling portrait of mid-20th-century Lithuanian violin virtuoso Jascha Heifetz, Peter Rosen’s doc God’s Fiddler attempts to penetrate what turns out to be the impenetrable: the cold surface of the man who wowed worldwide audiences with his bowing and plucking since the age of 17 but proved far less charming offstage. According to the film’s subjects (those who knew and studied with him), Heifetz was by turns a harsh taskmaster, a cold mentor, and an indifferent father—but also a man capable of surprising generosity and even the occasional bout of goofiness. The contradictions of the driven artist who both attracts numerous followers and alienates those closest to him are at the core of Rosen’s project, but as related primarily through eyewitness testimony, they don’t prove particularly enlightening, just the dull recollections of witnesses that fail to adequately evoke history or true character. The film only comes alive in the generous sampling of archival footage, both that taken by amateur videographer Heifetz himself and video recordings of the maestro at work. His lightning-fast fingers can’t fail to impress even those unschooled in the classical idiom, but when not center stage, Heifetz proves a far more elusive figure, firmly out of the grasp of Rosen’s film.