Shadows has made guest appearances on numerous albums by various artists. He also produced The Confession's 2007 album, Requiem, which, according to an interview, was one of the first steps which led to Avenged Sevenfold self-producing their 2007 self-titled album.
In October 2002, the band announced that Shadows was experiencing problems in his vocal cords, due to their active touring, and that his doctor advised him to take a short break from touring to prevent further damage[1]. After the release of City of Evil a false rumor started circulating, saying that the reason that he dropped screaming vocals was either due to a ripped vocal cord or a blown blood vessel in the back of his throat. This, however, is not true. Despite having a blood vessel removed from his vocal cords that would flame up and close his throat he still displays some screaming and growling in songs recorded after Waking the Fallen. Examples include the opening to Critical Acclaim from their self-titled album and God Hates Us from Nightmare.[2] In an interview on All Excess, manager Larry Jacobson states that Shadows had decided two years before the making of City of Evil that it would be an all-singing album. He had made it clear to their producer, Andrew Murdock, that the album they were working on at the time, Waking the Fallen would be half singing and half screaming, and that the next would be all singing. Moreover, Jimmy "the Rev" Sullivan confirmed that M. Shadows grew tired of doing screamed vocals.[3] In the past Shadows would sing on all parts of the songs during live performances, supporting the theory that he was no longer able to perform unclean vocals. Shadows has since resumed screaming again during live performances in the songs that initially feature screamed vocals[4]. In the band's fifth album Nightmare, Shadows has also re-incorporated some screaming vocals, notably on the song "God Hates Us."
