After guitarist Tim Agnello left Exodus in 1981, Holt joined the band and has been the main songwriter and the most senior member of the group ever since.

Holt was later confirmed to be a permanent member of Slayer, following Hanneman's death on May 2, 2013, and stayed with the band until their split, following the conclusion of their 2018–2019 farewell tour.

Before using the Silver Jubilee, DSL100H and Marshall JVM amps with Slayer, Holt made use of Jeff Hanneman's touring rack.

Holt's main guitar influences are Ritchie Blackmore, Michael Schenker, Angus Young, Tony Iommi, Uli Jon Roth, Matthias Jabs and Ted Nugent.

[6][7] His favorite bands include Venom, Motörhead, Black Sabbath, early Iron Maiden and Judas Priest.

[8] According to Holt, the track "War Is My Shepherd" on the album Tempo of the Damned is a treatise of America's "pro-God" and "pro-war" stance and how he feels the two beliefs are incompatible with each other.

[13] Exodus Slayer Asylum Destruction Heathen Hypocrisy Laughing Dead Metal Allegiance Panic Under Warbringer Witchery