Brian Douglas Wilson is an American musician, singer, songwriter, and record producer who co-founded the Beach Boys. Often called a genius for his novel approaches to pop composition, extraordinary musical aptitude, and mastery of recording techniques, he is widely acknowledged as one of the most innovative and significant songwriters of the 20th century. His best-known work is distinguished for its high production values, complex harmonies and orchestrations, layered vocals, and introspective or ingenuous themes. Wilson is also known for his formerly high-ranged singing and for his lifelong struggles with mental illness.