Question: Spike Slawson and Kirk Windstein, are both artists in which occupation?

Context articles: Kingdom of Sorrow
Down IV – Part I
Kirk Windstein
Uke-Hunt
Filthy Thieving Bastards
Spike Slawson
Behind the Blackest Tears
Pepper Keenan
The Dwarves Must Die
Todd Strange

Kingdom of Sorrow is an American sludge metal band which features Kirk Windstein of Crowbar and Down, along with Jamey Jasta of Hatebreed.
Down IV – Part I (informally known as the The Purple EP) is the first EP by sludge/southern metal band Down.
 It was released on September 18, 2012.
 It is the first album featuring bassist Pat Bruders due to the departure of former bassist Rex Brown in 2011, and the last to feature guitarist Kirk Windstein, who left in 2013.
Kirk Windstein (born April 14, 1965) is an American musician.
 He is a founding member of the sludge metal band Crowbar, and formerly played with the heavy metal band Down from 1991 to 2013.
 In 2005, Windstein formed Kingdom of Sorrow with Jamey Jasta of Hatebreed.
 Their debut album was released in 2008.
 Windstein began his musical career in 1985 as a guitarist for a cover band called Victorian Blitz, and in 1988 joined a hardcore punk band called Shell Shock as a vocalist and guitarist.
Uke-Hunt is a ukulele-based cover band fronted by Spike Slawson from Me First and the Gimme Gimmes.
 Although both this and the Gimmes are cover bands, they have very different approaches.
 While the Gimmes generally pick non-rock songs and rock them out and speed them up to turn them into punk music, while in this band, the songs picked are generally upbeat songs that are then slowed down and mellowed out.
The Filthy Thieving Bastards is an American folk/punk rock group formed in 2000 in San Francisco, California.
 The band was originally a side project put together by Johnny Bonnel and Darius Koski of the Swingin' Utters.
 Spike Slawson (also from Swingin' Utters) later joined the band, along with recording engineer Randy Burk.
 Greg Lisher from Camper Van Beethoven guested on guitar for several songs on their second release.
 Their music is influenced by folk rock, Celtic rock, country music, 60's pop, and punk rock, with an acknowledged and oft-noted debt to the music of The Pogues.
Spike Slawson is an American punk rock musician, a member of Me First and the Gimme Gimmes, Swingin' Utters, Filthy Thievin' Bastards, Re-Volts, and Uke-Hunt.
Behind the Blackest Tears is the second studio album by Kingdom of Sorrow, a group featuring Jamey Jasta of Hatebreed and Kirk Windstein of Crowbar and Down.
 The album was released by Relapse Records.
Pepper J. Keenan (born May 8, 1967), is an American guitarist and vocalist, best known for his work with heavy metal bands Corrosion of Conformity and Down.
 He joined Corrosion of Conformity in 1989, but did not become the lead singer until the recording of "Deliverance" in 1994.
 In 1991 he formed Down with Phil Anselmo of Pantera, Jimmy Bower of Eyehategod, and Kirk Windstein and Todd Strange of Crowbar.
The Dwarves Must Die is the 2004 release by the American punk band Dwarves.
 It is the band's first release on the "Sympathy for the Record Industry" label.
 There are several cameos, including Dexter Holland from The Offspring, Nash Kato from Urge Overkill, desert rock icon Nick Oliveri, Josh Freese from The Vandals, Spike Slawson from Me First and the Gimme Gimmes, gangster rapper San Quinn, DJ Marz, and even the original Space Ghost himself, Gary Owens.
 The rather freeform departure from the standard thrash/punk/noise sound is obvious in this release, slightly more so than in previous Dwarves productions, perhaps because they have been producing music for almost 20 years; however the original sound of the Dwarves shows clearly in several tracks.
Todd Strange (born January 31, 1966) is a bassist who played live on the first Down album "NOLA" and with Crowbar.
 Forming Crowbar with Kirk Windstein (Down), Matt Thomas and Craig Nunenmacher (Black Label Society), they released the best-selling albums of the band's discography.
 This included the Crowbar self-titled LP with the hits "All I Had (I Gave)", "Existence is Punishment", "No Quarter" (by Led Zeppelin) and "I Have Failed", produced by Phil Anselmo.
 By 1994, Phil put his band Pantera to the side and resurrected Down which was sidelined for Pantera in the late 1990s.
 The band released NOLA in reference to the band's hometown, New Orleans, Louisiana, and played 13 shows.
 Eventually, the album sold 500,000 copies and was certified Gold by the RIAA.
 Soon after, Phil returned to Pantera and Crowbar continued, and the two bands partnered up for tours in 1996.
 As a result, Todd, Kirk and the rest of Crowbar appear in Pantera's "Home Videos 3" in the credits, and Kirk and the band are seen in scenes including the notorious clip of Kirk dressed up as the Hulk.
 This event is also included in Crowbar's 1996 home video "Like Broken", but contains slightly different footage.