There are more than 6,000 names in Joel Katz’s Rolodex. One name was there first, and the rest followed: James Brown.

The late, legendary performer whose life story will be portrayed in the film “Get on Up,” opening Friday, was Katz’s very first client and a friend for more than 30 years.

“He used to tell people, ‘I started Joel Katz!’” the entertainment super-lawyer said Tuesday after speaking at summer commencement at Kennesaw State University (home of the Joel A. Katz Music and Entertainment Business Program, located about 15 miles north of Joel Katz Parkway in Atlanta). “He was very smart. He was not educated, but he had a Ph.D. in streetology. He taught me so much.”

Katz, who received an honorary doctorate from Kennesaw State on Tuesday, was not consulted about the movie and hasn’t seen it yet, but said his client would have loved seeing his life story on the big screen.

The most key lesson Brown ever taught him, he said, was patience.

“He would always tell me, ‘Don’t rush anything. Watch me on stage. Everything I do is for effect,’” Katz said.

Katz is the chairman of the Global Entertainment and Media Practice at the law firm Greenberg Traurig and former chairman of the American Bar Association’s Entertainment and Sports Law Section. His client list is packed with music industry giants like Justin Timberlake and Ludacris, and reading his list of board memberships and industry accolades would take longer than his commencement speech lasted.

Things looked vastly different at the dawn of his legal career more than four decades ago.

“I started with absolutely nothing,” said Katz, who got through law school at the University of Tennessee thanks to a scholarship and a six-day-a-week job working 6 p.m. to 6 a.m as a Holiday Inn night clerk. Graduation in 1969 brought him to a one-bedroom apartment in Atlanta and a teaching job at Georgia State University.

In 1971, he opened a law practice. He had a tiny office, a secretary he shared with other lawyers and one big problem: “I had no clients.”

One afternoon, the telephone blessedly rang. A banker on the line had taken Katz’s course at Georgia State and enjoyed it. Now he needed to help a client locate a good entertainment lawyer.

“Do you know anything about entertainment law?” the banker asked. Katz pondered that for a second. “I was honest: ‘No, I know nothing.’”

This, somehow, was the right answer. The next day, he was ushered into the penthouse suite at the Omni where Brown was getting his hair done.

“I was in awe,” Katz said. After a 10-minute discussion, Brown decided Katz was his man and stroked a retainer check for $2,500. The next day, they headed for New York, where Katz’s job was to negotiate a huge recording contract.

“He wanted $5 million and a jet plane, and a variety of other contractual demands,” Katz said. Recording executives were gobsmacked.

“No one who understood the recording industry would ask for such crazy things,” Katz recalled one of the executives bellowing. “As his yelling intensified, I began to realize why Mr. Brown chose me.”

After Brown signed the contract giving him most of what he wanted, Katz accompanied him to a news conference where Brown closed by saying, “I want to thank my lawyer, Joel Katz, from Atlanta, Georgia, the best entertainment lawyer in the whole world,” recalled Katz, who collected $50,000 for his work on that contract and remained Brown’s lawyer until he died on Christmas Day 2006. “The Atlanta Constitution and several other newspapers carried articles and my name was in all the articles: Joel Katz, the best entertainment lawyer in the world. A few days later, I received a call from a country music artist from Austin, Texas. He had read the articles. He said if you’re good enough for the Godfather, you’re good enough for me. Willie Nelson went on to be a superstar, too.”

A slew of others followed, and Katz’s clients have included Michael Jackson, Kenny Chesney, Julio Iglesias, Tammy Wynette, Kris Kristofferson, George Strait and George Jones.

“What I learned that helped me can help you,” Katz told KSU’s graduates. “Learn the gift of patience. The tortoise will win every single race. It is the interactions between human beings that creates relationships.”