Brett Morgen’s Kurt Cobain: Montage of Heck has all the subjects you’d expect: Cobain’s widow Courtney Love , Cobain’s parents and Nirvana bassist Krist Novoselic — everyone except Nirvana drummer Dave Grohl. Turns out Grohl was interviewed for the film, but not soon enough for the cut that received its world premiere Jan. 24 at Sundance Film Festival. Morgen interviewed Grohl in early January, too late to make this cut. At the Marc Theater premiere, Morgen said: “We had a locked print and trying to re-edit a film with a new interview in 10 days is kind of difficult.” Morgen did leave open the door that his footage could appear in other editions of the film, which premieres on HBO May 4.