Guitarist, singer, and songwriter Cesar Rosas is a key member of Los Lobos. While less prolific than the team of David Hidalgo and Louis Perez, his rootsy compositions, fiery guitar playing, and gritty vocals act as an important counterweight in the band's sonic blend. Primarily working from a blues-based foundation, Rosas' compositions for Los Lobos include the hard-rocking "Don't Worry Baby" (from How Will the Wolf Survive?) and "I Can't Understand", co-written with blues giant Willie Dixon, which appeared on The Neighborhood (1990). In addition to his role in Los Lobos, Rosas also appeared in 1998 as a member of Los Super Seven, the Latin American supergroup. Their album featured re-interpretations of traditional Mexican folk songs. In 1999 Cesar Rosas released his debut solo album, Soul Disguise, a potent blend of rock, blues, soul, and Mexican music.