Here's the song in Army of the Dead's appropriately epic teaser trailer. While Zack Snyder might be busy with Mother Boxes and cosmic treadmills thanks to the impending release of Zack Snyder's Justice League, the director isn't merely revisiting his past in 2021. Army of the Dead is Snyder's first feature film since Batman V Superman: Dawn of Justice in 2016 (although he's credited on the theatrical Justice League cut) and the Netflix movie is set for a May 21 premiere, with Snyder also producing and co-writing the effort. While plot details remain scarce, an impressive cast that includes Dave Bautista, Tig Notaro and Garret Dillahunt will attempt the ambitious task of robbing a casino in the midst of a zombie apocalypse.

The Army of the Dead trailer is now here, raising the stakes on this undead heist flick. The teaser footage introduces Bautista's gun-toting Scott Ward, Omari Hardwick's Vanderohe, and Matthias Schweighöfer's Ludwig, who has apparently taken to wielding a spiked baseball bat as his weapon of choice. The devastated Las Vegas landscape is impressively foreboding, and Army of the Dead promises to throw in flashbacks that explore the beginning of the outbreak, as well as following the high risk operation in the present day.

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Among the flailing bodies and flying bullets, a timeless voice rises above the chaos. The Army of the Dead trailer is set to a slightly rejigged, slowed-down version of Judy Garland's "Lucky Day." The song was written in 1926 and recorded by various artists including Harry Richman and The Revelers, but perhaps the most famous performance (and the one Zack Snyder uses here) is Garland's, first recorded in 1956.

Army Of The Dead Ludwig

"Lucky Day" is clearly a reference to Army of the Dead's Las Vegas casino setting. Over the years, the song has become synonymous with Vegas as the gambling capital of the world, evoking imagery of the "good old days" as tipsy gamblers whistle "this is my lucky day" while collecting their winnings. In Army of the Dead, the song takes on a much darker, ironic quality. Garland's classic vocals invite viewers to remember better times, but in this case, those "better times" are the days before zombies took over. And, of course, there's nothing lucky about being caught in the middle of a horde during a zombie apocalypse with only a baseball bat and a former WWE superstar to defend yourself.

"Lucky Day" continues a long-standing tradition of Zack Snyder trailer songs. The director typically pairs intense slo-mo action with calm, sedate music to create a juxtaposition of sound and image. Previous examples include "Hallelujah" in the Snyder cut trailer, "Come Together" in Justice League, the haunting, ethereal vocals of Man of Steel, and Watchmen's slowed down "The End of the Beginning is the End" by Smashing Pumpkins (which, incidentally, first appeared on the Batman & Robin soundtrack). "Lucky Day" has a similar effect for Army of the Dead, and perfectly matches the trailer's stark contrast between the swathes of dead bodies, and the bright, colorful vitality of Las Vegas.

More: Why Zack Snyder's Army Of The Dead Could Give Netflix A Whole New Audience