Ask Richard S. Busch, the lawyer who last week won a nearly $7.4 million copyright suit against Robin Thicke and Pharrell Williams, why he is so successful, and he will mention the 1997 film “The Devil’s Advocate,” in which Al Pacino plays Satan posing as a master lawyer.

In one scene, a modestly dressed Mr. Pacino shares a secret with his stylish and polished protégé, played by Keanu Reeves. “I’m a surprise,” Mr. Pacino tells him. “They don’t see me coming.”

“I think that’s me,” Mr. Busch, a partner in the firm King & Ballow in Nashville, said the other day with a laugh. “I’m sure Pharrell Williams and Robin Thicke said, ‘Who’s this guy from Nashville, Tenn.?’ They didn’t see me coming.”

Mr. Busch is not a surprise any longer. In one of the most important copyright cases in the music industry in years, he triumphed over Mr. Williams and Mr. Thicke and their elite Los Angeles law firm, convincing a federal jury that the songwriters’ 2013 hit “Blurred Lines” had too closely copied Marvin Gaye’s 1977 song “Got to Give It Up.”

In truth, the lawyers representing the two musicians knew exactly who Mr. Busch was. In the small world of high-powered entertainment lawyers, Mr. Busch, 49, has carved out a niche as a crusading outsider, winning cases that have had wide-ranging repercussions for the music industry. Among them are Bridgeport Music v. Dimension Films, which established that even the tiniest sample — a piece of one song used in another — needs legal permission, and F.B.T. Productions v. Aftermath Records, which led to a wave of litigation over how royalties are paid in digital music.

Compared with the polished style of many of the Hollywood litigators he has faced in court, Mr. Busch is a bit rough around the edges. One of his former clients, Joel Martin of F.B.T. Productions, a company connected to Eminem, proudly calls Mr. Busch “a street fighter.” He is known for extensive preparation and an aggressive style in depositions. At the “Blurred Lines” trial, he spoke so intensely that his voice cracked and the judge, John A. Kronstadt, repeatedly told him to slow down.

By comparison, Mr. Busch’s opponent in the case, Howard E. King of the firm King, Holmes, Paterno & Berliner, is a consummate industry insider, with an affable and sometimes sarcastic approach. In a sign of how familiar he was in the courtroom, Judge Kronstadt at one point joked that Mr. King need not worry about wearing a jacket the next morning because the jurors would not be able to see him as they entered through a side door.

Janis Gaye, the former wife of Marvin Gaye, said Mr. Busch’s distance from the center of the industry was one of the reasons that she and her children had hired him.

“He’s not one of the Hollywood mover-and-shaker guys who shows up at every party and says, ‘Hey, here’s my business card,’ ” Ms. Gaye said. “I’ve never met anyone like Richard Busch, and that’s fine with me.”

As Mr. Busch sees it, that works to his benefit. “By being on the outside,” he said, “everyone who hires me knows that they get 100 percent of my loyalty.” Many top entertainment lawyers see themselves primarily as deal makers, whose connections to both artists and the studios and record labels that hire them are often viewed more as synergy than as conflicts by those involved. And even the tough-minded litigators among the core firms seldom push against the status quo quite as aggressively as someone like Mr. Busch.

“Talent does not want to sue the record companies, for fear of being blackballed,” said the Los Angeles lawyer Neville L. Johnson, who represents actors and musicians. “You can’t sue the hand that feeds you.”

Mr. Busch said that an important part of his courtroom strategy is connecting with the jury. That may have been an advantage in the “Blurred Lines” case. He pounced on the changing accounts by Mr. Thicke and Mr. Williams of how the song had been written as undermining their credibility.

“You have to be the truth teller,” he said in an interview last week. “Some lawyers I have gone up against are perhaps more technically proficient, but I feel like I’ve done a very good job of connecting with the jury and being sincere in everything that I do.”

Other lawyers describe Mr. Busch with words like bully — not always insults in the legal field — and complain he is so aggressive in fighting for his clients that he does not care what havoc is created along the way. But they afford him grudging respect. The nearly $7.4 million in the “Blurred Lines” case, a combination of damages and a share of the profits Mr. Williams and Mr. Thicke received, is one of the largest awards for a case of its type, legal specialists said.

“He’s a tough competitor,” said David M. Given of the firm Phillips, Erlewine, Given & Carlin in San Francisco. “But I think it’s fair to say that his outside status, if you want to call it that, has empowered him to take on institutions and players in the music business that others wouldn’t.”

Mr. King declined to comment about Mr. Busch, but said that he expected to file a variety of post-trial motions to fight the decision.

Mr. Busch, who lives outside Nashville with his wife and three children, came to the music business by chance. After graduating from Loyola University New Orleans College of Law he joined King & Ballow in 1991 and was eventually connected with Bridgeport Music. It controlled music by funk acts like Parliament-Funkadelic and the Ohio Players that was being widely sampled in rap songs without permission, and wanted to pursue litigation, Mr. Busch said.

He filed suit against hundreds of opponents, with most cases resulting in settlements. One that went to trial, against the studio Dimension Films, resulted in a landmark appeals court ruling in 2005 that warned, “Get a license or do not sample.”

Just as that case did, the “Blurred Lines” verdict is now stoking concerns among advocates for artists that it could have hurt creativity.

“Both cases have lowered the threshold of what counts as copyright infringement,” said Kembrew McLeod, a professor of communications at the University of Iowa. “The ‘Blurred Lines’ verdict is gong to make songwriters paranoid about musical appropriation that could result in a lawsuit.”

The F.B.T. case, which Mr. Busch lost at the district level but later won on appeal with the help of another lawyer, Jerome B. Falk, had to do with how royalties are computed for downloads on stores like iTunes. The appeals court ruled that according to Eminem’s contract, these transactions counted as “licenses” rather than standard record sales — a category that, in Eminem’s case, triggered significantly higher royalty rates.

As a result of that ruling, dozens of artists filed suits against their record companies in 2011 and 2012; at least 20 of them were handled by Mr. Busch’s and his firm, he said.

After the “Blurred Lines” case was decided in the Gaye family’s favor last week, Mr. Busch said, his firm’s phone began to ring yet again, this time from songwriters looking to sue over what they argued was copyright infringement. He and his colleagues are combing through the submissions.

“I only take on cases,” Mr. Busch said, “that I believe I can win.” [New York Times]