Crooker's music career spans several decades, beginning with his synthpop band
Disjointed Images in 1989. His main solo project is
Symbion Project which was formed in 1993 and has released eleven full-length albums:
Red (1998),
Immortal Game (2003),
Wound Up by God or the Devil (2006),
Misery in Soliloquy (2009),
Contrapasso (2011),
Semiotic (2015),
Arcadian (2016),
Gishiki (2017),
Backscatter (2019),
Saturnine (2022), and
Tryptych (2025). In April 2017, Crooker teamed with Micah Knapp and Avielle Heath to create a 360 Virtual Reality music video for a single off of "Arcadian". In 1999, Crooker formed the
synthpop group
Freezepop with
Liz Enthusiasm and
Sean T. Drinkwater. While in the band he went by various aliases, starting as
The Duke of Candied Apples, then briefly being known as
The Duke of Belgian Waffles, and finally
The Duke of Pannekoeken. In September 2009, Crooker retired from Freezepop to focus his efforts on his work at
Harmonix. He has made several guest appearances at Freezepop concerts since then, often also playing a Symbion Project set. Other active bands include
ELYXR, Rocococo, Dispak, and
Black House Triangle. DJ HMX,
Komputer Kontroller, and
Cosmonaut Zero were alias monikers used only for the videogames
FreQuency (2001) and
Amplitude (2003). Several of his songs are featured in
Johannes Grenzfurthner's films
Die Gstettensaga: The Rise of Echsenfriedl,
Traceroute and
Glossary of Broken Dreams. His other former bands include the dreampop band Sirensong and the more well-known
Splashdown, whose albums include
Stars and Garters,
Halfworld (EP),
Redshift (EP), and the unreleased full-length albums
Blueshift (which was completed but never released by
Capitol Records) and
Possibilities (an album of remixes and demos). Other past bands include Larkspur, Khems, and The Planets Won't Let You Sleep Tonight. ==Video game development==