From PEOPLE Magazine Click to enlarge
During his three decades at the helm of American Bandstand, Dick Clark showcased hundreds of singers from Buddy Holly to Michael Jackson, introduced America to dance crazes and even helped integrate TV. "He wasn't one to take no for an answer. When he decided to revolutionize the music business, he did it," says Clark's longtime director Jeff Margolis. "We all say we went to the University of Dick Clark."

He certainly earned his reputation as a titan of two industries, changing the ways television and music worked-and worked together. Now both worlds are reeling from the loss of a legend: On April 18 Clark died of a heart attack after prostate surgery in Santa Monica. "Dick Clark was a pioneer," says Donny Osmond, who appeared on Bandstand and later worked with him on the talk show Donny & Marie. "Nobody establishes talent the way he did. Nobody mentors people the way he did. Who can replace him? No one."

Clark's ageless complexion and neatly groomed hairstyle spawned a generation of TV hosts-Ryan Seacrest calls him "my inspiration"-and earned him the nickname America's Oldest Teenager. "I kept my youth," he said in 2001, "because music has given me a youthful approach to everything."

But Clark's power went beyond appearances. At Bandstand, he had African-American artists perform their music (rather than having white artists cover the songs, then the norm) and invited African-American kids to dance on the show. "He made history, and I made history because of him," says singer Chubby Checker, whose "Twist" became a craze after he danced on the show in 1960. The only thing Clark refused to do was dance himself. "People expect me to dance well," he once confessed. "I don't dance. Period."

In later years his TV career evolved, as he hosted shows like The $10,000 Pyramid and Bloopers & Practical Jokes, founded the American Music Awards and produced countless TV programs, including his pet project Dick Clark's New Year's Rockin' Eve. Then in 2004 Clark, a diabetic, suffered a tragic setback: a severe stroke that left him partially paralyzed. "He was determined to get well and get back on camera," says Margolis. "His mind was so sharp, and he was not going to let his body take him down."

Although he continued struggling with his speech, Clark (who left behind his third wife, Kari, and three children) returned to TV in 2006, making annual Rockin' Eve appearances, with protege Seacrest stepping in as the main host. Despite his health battles, "he was so full of life," says singer Gloria Gaynor, a friend. "Dick Clark is one man you can actually say lived until he died."