Thériault began his professional musical career in 1984 at the age of eighteen in Jonquière, Québec. A co-founder and the bass player for VOIVOD, he toured internationally from 1982 to 1991. He is known in the metal world for playing with ferocious attack and for his trademark distortion - the "Blower Bass" sound. His signature bass guitar was designed for him by Mauro Liberatore, a five-string high B. Thériault wanted to play chords which would make the bass sound more like a guitar but bigger.
He composed and recorded six albums on MCA (USA), Noise International (Germany) and Metal Blade (USA) with guitarist Denis "Piggy" D'Amour, drummer Michel "Away" Langevin and singer Denis "Snake" Belanger. Voivod were exploring the concepts of Cyberpunk and state-of-the-art artificial intelligence long before these ideas were assimilated into popular culture.
A co-founder of The Holy Body Tattoo Dance Society, along with choreographers/performers Noam Gagnon and Dana Gingras, from 1992 to 1999 Thériault composed intensely resonant and evocative musical landscapes that left an indelible impression on the contemporary dance world. Through the use of electronic sampling, sequencing and programming, he produced and engineered the full length scores for "White Riot", "Poetry & Apocalypse" (co-composed with Craig Riddock) and "our brief eternity". He toured North America and Europe from 1996 to 1998 as both a sound engineer and a musician. Thériault was awarded 'Best Use of Sound/Music' in 1988 from the Canadian International Annual Film/Video Festival for the film version of "Poetry & Apocalypse".
In 1997 Thériault recorded the "The Electronic Voice Phenomena" CD with Mark Spybey, which was composed using sequencers, samplers, analog keyboards and various sound modules and devices. He continued to create experimental recordings in collaboration with Australian artist Matt Warren. In 2006 they created sound for the performance installation "BUG" presented at CESTA's (Tabor, CZ) 11th Arts Festival in 2006. In February 2008 they presented a piece titled "Hiatus" at Inflight Gallery in Hobart, Tasmania.
Thériault has engineered sound for rock acts such as extreme metal band MARTYR and Montréal hard rockers PRIESTESS. He performed in 2002 with the metal "supergroup" BLACK CLOUD, featuring Pierre Rémillard (OBLIVEON) on guitar, Daniel Mongrain (MARTYR) on guitar, Florent Mounier (CRYPTOPSY) on drums, and Patrick Mireault (GHOULUNATICS) and Marc Vaillancourt (B.A.R.F.) trading off on vocals.
In 2006 Thériault co-produced NEGATIVA's self-titled 3 song EP with Wild Studio's Pierre Rémillard. He recorded the bass track for "Brain Scan" with MARTYR, who included the VOIVOD cover on their latest release "Feeding the Abscess." Thériault performed live with the band at their record launch at Montréal's Medley on November 11, 2006.
In August 2007 Thériault was both the Technical Director and Sound Engineer for "25 ans du Métal Québécois," a three day event featuring twelve seminal Québec metal acts at Montréal's Club Soda. He took part in a medley of Voivod classics with a group that included Daniel Mongrain (MARTYR), Peter Jackson, and Martin Frechette. The performance was in honour of the late VOIVOD guitarist Denis "Piggy" D'Amour, who was inducted into the Quebec Metal Hall Of Fame.
Currently Thériault is playing live shows with Voivod. The band's line-up consists of Denis "Snake" Bélanger, Michel "Away" Langevin, Jean-Yves "Blacky" Thériault, and Dan Mongrain on Guitar.
Voivod performed at the Heavy MTL show in Montreal, Canada on the 22nd of June, 2008, and at the Monsters of Rock Festival in Calgary, Canada on July 26, 2008. Voivod supported Judas Priest at the Bell Center, Montreal, Canada on August 12th, 2008. They will perform full sets at Thrash Domination in Kawasaki, Japan, September 20th-21st, 2008, along with the bands Testament and Forbidden.
Thériault has agreed to contribute to the final Voivod studio album, which will contain tracks recorded by Denis "Piggy" D'Amour before his death.