Phil Spector with an oversized afro just made most of us laugh. But David Mamet, evidently, was inspired to write a film about it when pictures of the befuddled looking record producer emerged from his first murder trial in 2007. That wig provides Mamet with a key moment in his movie, which finally arrives on HBO on Sunday (March 24) with a wall of buzz behind it.

But wait—Phil Spector is not what you think. Beginning with a title card that states, "This is a work of fiction. It’s not ‘based on a true story...,'" Mamet’s film allows the writer-director to riff all over the place on the growing interference between myth, perception, and reality—a hot zone that goes off the scale at a celebrity murder trial.

Mamet imbues his version of Spector with more humanity than most of his real life acquaintances would allow; a point he demonstrates a number of times as Spector’s defense team tries vainly to gather positive testimony from his colleagues.

And while Phil Spector depicts the fallen mogul as paranoid, tempestuous, and megalomaniacal—a rant about Sidney Poitier at one point is definitely a keeper—he’s also a rational creature in his own off-planet way, even wise at times, not to mention witty and dashing enough to persuade his reluctant attorney, Linda Kenney Baden (Helen Mirren), to eventually shrug off her own biases against him. Hell, he might even be innocent.

You could complain that Mamet is asking to have it both ways when he creates his own parallel universe to query the elusive nature of truth, and he probably didn’t need to bash us over the head with all that 'Back to Mono' symbolism. Fortunately, Al Pacino’s ferocious performance in the title role—and I really must apologize for the cheap shot I took at the veteran actor here—is more than enough to compensate for this, and the oddly weightless, ultimately puzzling effect of Mamet’s curiosity piece.

Phil Spector premieres on HBO, on Sunday (March 24) at 9 p.m.