R. Crumb is the subject of a fine New York Times article. He is best known for his comic art which was most popular in the 1960s and 1970s.
He also is a musician and plays old blues songs. He designed a deck of cards of blues artists. I have included pictures of a large poster and small print based on them. I bought the poster from his website.
He was also the subject of an excellent 1995 documentary, Crumb, available on Blu-ray and DVD from the Criterion Collection.