Rush's look at the horrors of mob vengeance, "Witch Hunt," takes on Ozzy Osbourne's occult anthem "Mr. Crowley" in round one of our Rock's Scariest Song battle.

In honor of Halloween, we've chosen 16 of rock's scariest songs. The field will be sliced, diced and chopped in half every week based on your votes, until only the scariest song in rock history remains alive.

Although "Witch Hunt" was originally released as part of 1981's Moving Pictures album, it's actually part of a much broader work that spans four songs, spread out across four albums and released over a 21-year span. Dubbed "Fear," the song series started with "Witch Hunter," followed by "The Weapon" from 1982's Signals and "The Enemy Within" from 1984's Grace Under Pressure. Years later, it concluded with a fourth chapter, "Freeze," recorded as part of 2002's Vapor Trails. Despite the order in which they were released, the "Fear" tracks are arranged with "The Enemy Within" serving as the first chapter, followed by "The Weapon," "Witch Hunt," and "Freeze," all of them combining to address the idea that, as drummer Neil Peart later put it, "people don't make choices based on hope that something good will happen, but in fear that something bad will happen."

"Mr. Crowley," in comparison, is far less complex. Recorded for Osbourne's 1980 Blizzard of Ozz album, the song was inspired by the story of famous occultist Aleister Crowley, whose life Osbourne had recently read about, as well as a deck of tarot cards found at Ridge Farm Studio, where he was working on the album. Released as the album's second single, as well as the lead track on the subsequent Mr. Crowley Live EP, it helped drive Ozzy's post-Black Sabbath solo career to new multi-platinum heights.

You can listen to both songs below so you can make an informed choice. You can vote once per hour in each of the eight first round Rock's Scariest Song battles until polls close on Oct. 12 at 11:59PM ET. Your choice for Rock's Scariest Song of all time will be revealed on Nov. 1, 2015.

Listen to Rush's 'Witch Hunt'

Listen to Ozzy Osbourne's 'Mr. Crowley'