"Donny Kirshner would take a kid off the street, bring him up to his office in the Brill Building and turn him into Neil Diamond, Carole King, James Taylor, on and on," Wishna said. "I haven't spoken to anyone in the music business that Donny hasn't either discovered, promoted, or touched in some way.
"I've never seen anybody like this in my life," he said.
Kirshner was behind "Don Kirshner's Rock Concert" in 1972, and gave national exposure to musicians including Billy Joel and The Police. The show also boosted careers of comics including Billy Crystal, Arsenio Hall and David Letterman.
Paul Shaffer, Letterman's musical director, used to give a deadpan performance during his imitation of Kirshner on Saturday Night Live. Shaffer and Kirshner worked together on the short-lived sitcom, A Year at the Top, according to Shaffer's manager.
"Every dream I ever had as a kid, he was my genie," Orlando told AP.
Orlando said Kirshner was responsible for so many careers, "it would make your head spin."
"This was not just a song guy, this was a man who created the cornerstones of American pop music as we know it today," Orlando said. "Without Donny Kirshner, the music we know of today would not be the same. He was a game-changer, and I tell you that me and my family feel this tremendous loss for this man."
There was no phone number listed for a Don Kirshner in Boca Raton.
The Brill Building was a hit factory — notable for attracting songwriters, agents and others as tenants. More than 160 of its tenants were in the music industry by the early 1960s, according to New York's Landmarks Preservation Commission.
Wishna said Kirshner was a mentor who knew the art of discovering talent and cared about the artists he worked with.
"He was a father to these people even though some of them were three or four years younger than him," Wishna said.
Wishna said Kirshner was a pioneer who developed a system for singer-songwriters to share in the profits of selling music.
Howard Kramer, curatorial director at the Rock and Roll Hall of Fame, said Kirshner will be most remembered for "nurturing and developing an early, unprecedented amount of artists, mostly songwriters, and also a television pioneer for bringing live rock 'n' roll to television."
Kirshner also ran three labels, Dimension Records, Colgems Records and Kirshner Records.
Before he died, Kirshner was chief creative officer of Rockrena, a company launching this year to find and promote talent online.