Leprous is a Norwegian progressive metal band formed in 2001 by singer and keyboardist Einar Solberg and guitarist Tor Oddmund Suhrke. After releasing several demos with relatively unstable lineups, the band released their first studio album, Tall Poppy Syndrome, in 2009. They subsequently gained prominence as the live backing band of Ihsahn, who, in turn, contributed on several Leprous records as guest singer or producer. Their acclaimed 2011 album Bilateral led to further attention.