With his band My Darkest Days, this Canadian rock vocalist recorded a 2012 album, Sick and Twisted Affair, that rose to #29 on both Canadian and American music charts. His band's debut, self-titled album reached #11 on Canadian charts and #38 on U.S. charts.
He formed My Darkest Days in 2005. Three years later, the band's song "Every Lie" won an Ontario FM radio station's "Rock Search" music contest.
One of his band's singles was featured on the soundtrack of the 2010 horror film Saw 3D.
His brother, Brad Walst, became famous as the bassist of another Canadian band called Three Days Grace. Matt later joined Three Days Grace as the group's frontman.
His 2010 track "Porn Star Dancing" became a U.S. Gold and Canadian Platinum recording and featured additional vocals by Chad Kroeger.