The soul singer Lester Chambers was allegedly assaulted at a concert on Saturday night, after he dedicated a song to Trayvon Martin. Hours after George Zimmerman was acquitted for Martin's murder, the leader of the Chambers Brothers was attacked by a woman shouting: "It's all your fault."

According to the Contra Costa Times, the incident occurred midway through Chambers' performance at the Hayward-Russell City Blues festival, in California. Introducing a cover of Curtis Mayfield's People Get Ready, Chambers said that if Mayfield were still alive, the lyric "there's a train a-comin'" would be changed to "there's a change a-comin'", in response to Martin's death.

Almost immediately Dinalynn Andrews Potter leapt on to the stage – "like an acrobat", according to Chambers' wife. "She had a crazed look in her eye," a witness told the Times. "I saw the devil there." She shoved the singer before anyone else could react; Chambers, 73, was eventually taken to hospital, receiving treatment for "bruised rib muscle and nerve damage". Andrews Potter, 43, was arrested and charged with suspicion of battery, while Chambers "will be up and running soon", according to his son.

Many other musicians paid tribute to Martin this weekend, albeit in more peaceful circumstances. Beyoncé took the stage in Nashville 30 minutes after the jury in Florida had returned with its ruling, ending the three-week trial. Under low lights, she asked the audience to "have a moment of silence for Trayvon". Following a long pause, she performed a solemn rendition of the chorus from I Will Always Love You, then transitioned into her hit Halo.

The following night, Beyoncé's husband offered his own homage to the 17-year-old. Jay-Z took a few seconds amid the glitz and thump of his final Wireless festival set, saying, "Rest in peace, Trayvon Martin." The rapper had previously criticised the coverage of Zimmerman's trial, complaining to Hot 97 that TV networks were reducing justice to "entertainment". "CNN is almost like TMZ," he said. "It's really all for ratings."

One of Wireless's other performers, A Tribe Called Quest, dedicated their entire set to Martin. "I don't want to be a downer but yesterday, in America, we saw a miscarriage of justice," Q-Tip said on Sunday. "It's not the first time this has happened. Pray for us … we need help."

Other musicians responded to the jury's decision over Twitter. "Shit [don't] change, and I may never get to see it do so. I pray 4my kids & yours," wrote Lil Wayne. "Bullshit!" tweeted Chris Brown. Rihanna called it "the saddest news ever", while Miley Cyrus said she felt "sick".

"Black parents hug your sons right tonight. Let them know their value. This ain't a black or white thing this is a wrong and right thing," wrote Talib Kweli, while Solange Knowles suggested: "We have to somehow turn this anger & pain into peaceful productivity." But Lupe Fiasco said he accepted the not guilty verdict. "Nobody knows what really happened except Trayvon and Zimmerman," he wrote. "The justice system relies on reasonable doubt not our emotions … Emotional reactions to a perceived injustice will get you nowhere."

Zimmerman was arrested and charged in April 2012, 44 days after shooting Martin dead. The jury of six women agreed with Zimmerman's contention that he had acted out of self-defence, believing that the hoodie-clad teen was going to kill him. On Saturday, Martin's father said he was "brokenhearted" by the decision.