By JASON COMERFORD

Bob Clark’s 1974 film Black Christmas has withstood the test of time that makes mincemeat of so many other horror efforts; even today, over three decades later, it’s an oblique freak-out that still has an unsettling power. Of particular note are the disturbing obscene phone calls from “Billy,” the unseen psychopath menacing a houseful of sorority sisters; largely improvised but carefully crafted by Clark, actor Nick Mancuso and others over the course of several days during postproduction, the unnerving vocal attacks seem almost as assaultive as the physical violence that later ensues.

But the coldest hand on your neck belongs to that of Carl Zittrer, whose unrelenting musical assaults are as genuinely frightening as anything ever written for a horror film before or since. Zittrer, who has many credits in a long career as a composer, music editor and music supervisor, related the story behind the music in a filmed Q&A session included as a bonus feature on the recent DVD and Blu-Ray releases of the film:

Some of the sounds were - this was in the day, as everybody here will know, before samplers, before synthesizers, so much of these sounds came from a piano that I destroyed. I scraped it with combs and brushes and forks, and recorded it as many ways as I could think of -- reversed it, put it through reverb, sent it to a recording studio, had other things done to it -- that any of it survived all that mangling is really quite surprising. But they were mostly concrete sounds that you find anywhere, and then, we manipulated them. And much of it was voices, sometimes -- ...vocals sung into the piano to excite the strings of the piano, recorded backwards -- anything you could think of, we did to the sound. I'm glad it worked for you. I was never sure at the time.

Zittrer’s score for Black Christmas is one of the great unreleased treasures of horror film music, and until that situation is remedied by one of your favorite film music labels, the best place to experience it is within the film proper. Just don’t go exploring in the attic...

Great movie.