In an interview, Killer Mike took a dim view of the Supreme Court, saying it had gutted the Voting Rights Act. But he held out hope that the justices would treat the violent images in Mr. Bell’s song no differently than they would similar ones in folk, country, reggae — or opera.

“Anyone who is learned in law,” Killer Mike said, “is capable of separating art and lyrics, whether you agree with them or not, and actual human behavior. I think the courts understand it when it’s Johnny Cash. I think they understand it when it’s Robert Nesta Marley.”

It is true that Johnny Cash did not actually shoot a man in Reno just to watch him die. Bob Marley did not actually shoot the sheriff. Treating rap lyrics differently, Killer Mike said, “persecutes poor young men based on their class and color.”

Mr. Bell, who raps as T-Bizzle, is now 22 and still pursuing a career in music. He sounded stunned on hearing the names of the stars who have come to his aid.

“It makes me feel like a kid in a candy store,” he said.

The case started in 2011, when Mr. Bell was a senior at Itawamba Agricultural High School in Fulton, Miss. (The school has been in the news before. In 2010, it canceled a prom rather than let a lesbian student attend with her girlfriend.)

After several female students said they had been subjected to sexually charged comments and unwanted touching from two male coaches, Mr. Bell recorded a song to address the complaints.