Blind Illusion, an American progressive thrash metal band from Richmond, California, was formed in 1978 by guitarist Mark Biedermann. The initial lineup included Les Claypool on bass and Bret Hern on drums. Blind Illusion began their career influenced by progressive rock bands such as Rush and King Crimson. In 1988, they released their debut album, The Sane Asylum, featuring Les Claypool on bass and contributions from Larry LaLonde on guitar, both of whom would later join Primus. The album was produced by Kirk Hammett of Metallica and included guest contributions from Joe Satriani and Robbie Krieger. Following the tour, Claypool and LaLonde departed to focus on Primus. Biedermann later reformed Blind Illusion in 2009, releasing Demon Master in 2010 and Wrath of the Gods in 2022.
