Karl Blau is an indie rock and folk musician based in Anacortes, Washington, USA, 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.