[6] Shadows possesses a baritone voice but is able to sing comfortably in the tenor range, hitting high C on a regular basis.

On the band's first full-length record, Sounding the Seventh Trumpet, he featured harsh, metalcore-style growls with limited instances of clean vocals.

However, the most significant change came with the release of the band's major label debut, City of Evil, in 2005, which featured minimal background screaming, stronger vocal melodies, and increased emphasis on harmonies and melodic hooks.

[8] Shadows was specifically looking to add a more gritty, raspy tone to his voice and worked with Anderson for several months on this before City of Evil was recorded.

However, producer Andrew Murdock put down these rumors by saying: "When I met the band after Sounding the Seventh Trumpet… Matt handed me the CD, and he said to me, 'This record's screaming.

During an interview with Stevie Rennie on October 28, 2014, Shadows mentioned he had intentionally changed his voice to become less raspy and distorted while touring in 2014.

Shadows has also been longtime friends with David Vonderhaar of Treyarch, the developers of the Call of Duty: Black Ops video game series, for which Avenged Sevenfold have created four original songs.

In 2012, Shadows and Synyster Gates made a brief cameo in Call of Duty: Black Ops II in which they provided the voice over and motion capture of themselves.

In July 2019, Shadows was added as a playable character in Call of Duty: Black Ops 4's "Blackout" battle royale mode.

[12] In June 2020, during the George Floyd protests, Shadows published an op-ed piece for Revolver announcing his support for the Black Lives Matter movement.

[13] His favorite artists include Guns N' Roses, Elton John, Pink Floyd, Bad Religion, Pennywise, NOFX,[14] At the Gates, Dream Theater, Helloween, Iron Maiden, Korn, Megadeth, Metallica, Pantera, Queensrÿche, System of a Down,[15] Mr. Bungle,[16] H2O,[17] Rancid,[18] Disembodied, and Knocked Loose.