"Hit the Lights" was based on an unfinished Leather Charm song written by Hetfield and Hugh Tanner. Hetfield had brought the majority of the song to Ulrich, and the two worked out different arrangements. Performed at 160 beats per minute, "Hit the Lights" opens with fade-in distorted guitars and a short shriek by Hetfield. The song is driven by the 16th note repeated main riff and the continuous eighth note snare drum hits. The lyrics celebrate heavy metal itself and are sung with short and high pitched vocals. The song ends with several lengthy guitar solos by Hammett, who performed cleaner and more melodic versions of Mustaine's leads. "The Four Horsemen" is a revamp of the Mustaine-penned "The Mechanix", which originally had lyrics about having sex at a gas station. A modified version of his composition with the original lyrics appeared on Megadeth's debut "Killing Is My Business... and Business Is Good!" (1985). Although Mustaine told Metallica not to use any of his music, Hetfield wrote lyrics about the Four Horsemen of the Apocalypse and added a bridge and cleanly picked guitar solo in the middle. Mustaine said the bridge was inspired by the main riff in Lynyrd Skynyrd's "Sweet Home Alabama".