Karl Blau is an American indie rock and folk musician based in Anacortes, Washington, United States, and a member of the Knw-Yr-Own/K Records collective. His music is eclectic, incorporating elements of folk, dub, R&B, bossa nova, grunge, hip hop, drone and worldbeat.
Blau is a singer-songwriter who releases his music through a subscription service called the "Kelp Lunacy Advanced Plagiarism Society", retitled from "Kelp Monthly" as new releases were not produced and sent out on time. He has played in several bands over the years, such as D+, Brothers Blau, Captain Fathom and Your Heart Breaks. He also has collaborated extensively with other Washington-based musicians, including Phil Elvrum of The Microphones and Mount Eerie, LAKE and Earth. In addition, he has toured and recorded with Laura Veirs, whose career also began in the Pacific Northwest.
In December 2007, a grassroots online petition drive began gathering signatures urging Knw-Yr-Own Records in Anacortes to reissue the Shell Collection compilation of Blau's early 4-track recordings. As part of the campaign, Blau posted a statement on his MySpace page calling for the release of the album on vinyl, stating "everything sounds better on LP not to mention the art is bigger".
Blau was referenced in a song carrying his name by the London punk band Video Nasties. The Microphones' album, It Was Hot, We Stayed in the Water, also has a song titled "Karl Blau".