WEST HOLLYWOOD, Calif.

“Empire” actor Jussie Smollett was blunt, emotional and defiantly determined last Saturday night at a Southern California concert some urged him not to play, telling the crowd before singing a note that he had to go on with the show because he couldn’t let his attackers win.

“The most important thing I can say is thank you so much, and I’m OK,” the 36-year-old actor and R&B singer said from the stage at the Troubadour in West Hollywood. It was his first public appearance since he reported to police in Chicago on Jan. 29 that two masked men assaulted him and put a rope around his neck while using homophobic and racial slurs.

“I’m not fully healed yet,” said Mr. Smollett, who is openly gay, “but I’m going to be and I’m gonna stand strong with y’all.”

The concert had been planned long before the incident, and his family members and others had urged him to postpone it.

But Mr. Smollett said he couldn’t do that.

“I had to be here tonight, y’all. I couldn’t let those (expletives) win,” he said to screams and cheers from the packed room of about 400 people. “I will always stand for love. I will only stand for love.”

His small band then launched into an upbeat song and he broke into dance, wearing a simple white buttoned shirt, white sneakers and black jeans, shuffling across the front of the stage and at times standing with a fist in the air.

Mr. Smollett kept the tone mostly celebratory through his hourlong set before addressing the attack head-on toward the end of his set, when he told the crowd he wanted to clarify a few things.

He said he was bruised but his ribs were not cracked. He went straight to the doctor but was not hospitalized, and physicians in both Chicago and Los Angeles cleared him to play but told him to be careful.

“And above all, I fought the (expletive) back,” he said to cheers.

Then he paused and said, emphatically, but with a laugh, “I’m the gay Tupac.”

Fan Monique Davis said after the show that she was shocked he spoke so bluntly and directly about the incident, but she’s glad he did.

“It was amazing, it was emotional, it was inspiring,” Ms. Davis said. “He showed everyone in the room he was strong.”

Mr. Smollett told police the men attacked him as he walked home in Chicago, throwing a chemical substance at him in addition to shouting slurs and putting the rope around his neck.

No arrests have been made. Police have not found surveillance video of the attack, though they found footage of Mr. Smollett walking home with the rope around his neck.

Mr. Smollett had made his first public comments about the incident last Friday in a written statement that said he had been “consistent on every level” with the police during their investigation, countering comments on social media saying he had changed his story and been uncooperative with investigators.

Chicago police also said Mr. Smollett has been cooperative and they have found no reason to think he’s not being genuine.

Mr. Smollett stars alongside Terrence Howard and Taraji P. Henson in “Empire,” the Fox TV show about the power struggles of a family in the music business that is now in its fifth season. The series has allowed Mr. Smollett to play, sing and occasionally write music in addition to acting.

Last year, he released a solo album, “Sum of My Music,” which made up much of the concert, along with songs from “Empire.”

He often sits at the piano on the show, but stood front and center at the microphone at the Troubadour, the legendary Los Angeles club that helped launch the careers of James Taylor, The Eagles and Elton John.

He was joined in jubilant dance by his family members during his encore. Earlier, they had taken the stage and voiced their support before he came on.

“To be honest, as his big brother, I wanted him to sit this one out,” Joel Smollett Jr. said. “But we realized this night is an important part of Jussie’s healing. He’s been a fighter since he was a baby. He fought his attackers that night, and he continues to fight.”