A film derived from “thousands of hours” of rare and mostly previously unseen performance footage of David Bowie may premiere as early as January.

Variety reports that the as yet untitled project is being helmed by director Brett Morgen, whose resumé includes Kurt Cobain: Montage of Heck, Jane and The Kid Stays in the Picture. They say he’s been secretly working on it for the past four years with the “support and cooperation” of the Bowie estate.

The magazine quotes a source who says that the film is “neither documentary nor biography, but an immersive cinematic experience” based on the live footage. They also say that Morgen may be looking to premiere it at January’s Sundance Film Festival, and would like it to play at iMAX theaters.

Tony Visconti, who produced about a dozen of Bowie’s album, is the film’s music producer.