Opening and closing tracks "Angel of Death" and "Raining Blood" are the most (in)famous songs off of the album. Arguably the single greatest Slayer song, the Hanneman-penned "Angel of Death" opens with one of the band's most instantly recognizable riffs, shortly followed by one of Araya's most piercing screams ever. The lyrics are among the most grotesque in the Slayer catalogue, documenting the experiments of Nazi doctor Josef Mengele performed on prisoners at Auschwitz. Despite being the album's most melodic song (relatively speaking), "Raining Blood" is one of the band's most avant-garde tracks. Opening with a clap of thunder, distant, tribal drumming, and disembodied guitar squeals, the extremely catchy main riff is the only part of the song that the band returns to throughout its duration. Containing no clear structure and some very abstract, apocalyptic lyrics, the song rapidly descends into an out-of-control mess of whammy bar dives before being abruptly cut off by another thunder clap, closing the album with the sound of falling rain. The other songs aren't quite as remarkable, but what's surprising is how catchy that they turn out to be despite being devoid of any normal concept of melody as well as lasting the average time of most hardcore punk songs.
Unsurprisingly, 'Reign in Blood' was a bit controversial upon its release due to its graphic lyrics and cover art, but it ultimately made Slayer more successful due to the increased public interest. While Slayer has never fully gained mainstream acceptance (at least not to the level of the other three of the Big Four), they possibly have been the most innovative and have made the biggest impact on the future of heavy metal in general, and this album stands as a catalyst for that evolution. Still brutal to this day, 'Reign in Blood' is an essential metal album.