Kjartan Sveinsson, born in 1978 in Iceland, is a multi-instrumentalist known for his role as the keyboardist of the post-rock band Sigur Rós. He contributed to their distinctive sound with various instruments, and his early work with the band included notable studio albums such as Ãgætis byrjun and Takk.... He composed scores for films including the Academy Award-nominated short film SÃðasti bærinn (The Last Farm, 2005) and Ramin Bahrani's 2009 short film Plastic Bag. In addition to his work with Sigur Rós, Sveinsson collaborated on various projects, such as performing under the pseudonym "The Lonesome Traveller" and contributing to The Album Leafâs album In a Safe Place. He left Sigur Rós in 2013 but returned to the band in February 2022.