« James « Jim » Flora (January 25, 1914 ‒ July 9, 1998), best known for his distinctive and idiosyncratic album cover art for RCA Victor and Columbia Records during the 1940s and 1950s, was also a prolific commercial illustrator from the 1940s to the 1970s and the author/illustrator of 17 popular children’s books. Less well-known is that he was a fine artist with a diabolical bent, who created hundreds of paintings, drawings, etchings and sketches over his 84-year lifespan. » Wikipedia
I think he was one of the most important illustrator of the 20th century.
Nowadays a lot of works seems directly inspired by him.
I let you appreciate some of his art below and have a look to his webpage !