Milton Glaser, the groundbreaking graphic designer who adorned Bob Dylan’s silhouette with psychedelic hair and summed up the feelings for his native New York with “I (HEART) NY,” died Friday, on his 91st birthday. The cause was a stroke and Glaser had also had renal failure, his wife, Shirley Glaser, told The New York Times. In posters, logos, advertisements and book covers, Glaser’s ideas captured the spirit of the 1960s with a few simple colors and shapes. He was the designer on the team that founded New York magazine with Clay Felker in the late ’60s. His pictorial sense was so profound, and his designs so influential, that his works in later years were preserved by collectors and studied as fine art. But he preferred not to use the term “art” at all. “What I’m suggesting is we eliminate the term art and call everything work,” Glaser said in an Associated Press interview in 2000, when the Philadelphia Museum of Art hosted an exhibit on his career. “When it’s really extraordinary and moves it in a certain way, we call it great work. We call it good when it accomplishes a task, and we call it bad when it misses a target.” The bold “I (HEART) NY” logo – cleverly using typewriter-style letters as the typeface – was dreamed up as part of an ad campaign begun in 1977 to boost the state’s image when crime and budget troubles dominated the headlines. Glaser did the design free of charge. His 1966 illustration of Dylan, his face a simple black silhouette but his hair sprouting in a riot of colors in curvilinear fashion, put in graphic form the 1960s philosophy that letting your hair fly free was a way to free your mind. (For him, though, it wasn’t a drug-inspired image: he said he borrowed from Marcel Duchamp and Islamic art.) The poster was inserted in Dylan’s Greatest Hits album, so it made its way into the hands of millions of fans. Glaser was born in 1929 in the Bronx and studied at New York’s Cooper Union art school and in Italy. In 1954, he co-founded the innovative graphic design firm Push Pin Studios with Seymour Chwast and others. He stayed with it 20 years before founding his own firm. The Cooper-Hewitt, Smithsonian Design Museum awarded him a lifetime achievement award in 2004. In 2009, he was awarded the National Medal of Arts. “I just like to do everything, and I was always interested in seeing how far I could go in stretching the boundaries,” he said.