With an acoustic guitar, dreadlocks, and a flower child disposition, Jason Castro spun his singer/songwriter appeal into a fourth-place finish during American Idol's 2008 season. Castro was the first artist to play an instrument on the show, and he used his guitar skills throughout the competition, accompanying himself during laid-back performances of "I Shot the Sheriff," "Daydream," and "Travelin' Thru." Although he ultimately finished behind rivals Sayesha Mercado, David Archuleta, and David Cook, Castro still displayed his commercial potential with a pair of digital-chart hits, including a ukulele-helmed version of "Over the Rainbow" that topped digital charts. He then parlayed that success into a major-label deal with Atlantic Records, which signed the artist in April 2009 and issued his debut album the following year. Five tracks from that album also appeared on Who I Am, Castro's first contemporary Christian album, which appeared in November 2010. Castro returned with his third studio album, the similarly Christian-themed Only a Mountain, in 2013. ~ Andrew Leahey