"The Spheres Beyond Sound (Threnody)"

by Stephen Mark Rainey
originally published Deathrealm No. 2, Summer, 1987

Our narrator decided to spend a vacation visiting his late grandfather's old house, in a remote part of the Appalachian called Copper Peak.  The place is old and run down but liveable, and among the things he finds there is a very old book called The Spheres Beyond Sound by Maurice Zann, which alleges that certain combinations of tunings and tones can open up gateways to other worlds.  The book intrigues him.  Later he finds a recording grandpa made with some local musicians, experiments with Zann's pieces to see if they would indeed open gates.  It seems like nothing happened.

The next day, while exploring a local graveyard, narrator gets spooked and starts to flee.  He sees a growing blackness behind him and hears sounds like things digging out and shuffling after him.  Back at the house, he's confronted by a group of zombies and a giant, shadowy spider-thing looming over the house.  He flees, and escapes, but continues to believe that one day he too will become a zombie in thrall to the creature.

This story actually made something of an impression, in part because it manages to play with Derleth/Lovecraft clichés and make them sorta fresh.  The EC-like ending isn't exactly Lovecraftian, but it is kind of effective.  It's very pulpy but a lot of fun.