Thousands attend Nipsey Hussle's funeral at Staples Center in Los Angeles

The Grammy-nominated rapper was gunned down outside his store.

In life, Nipsey Hussle last took center court at the Staples Center on March 9 to perform during the halftime of a Clippers' NBA basketball game. In death, the Grammy-nominated artist filled the marquee Los Angeles venue on his own Thursday for his public memorial.

Fans of the rapper, who was gunned down in front of his South Los Angeles clothing store on March 31 at the age of 33, received free tickets to what was billed as a "celebration of life." The service got underway just after 10 a.m. local time with a performance of Hussle's hit song "Victory Lap" and mourners chanting, "Nipsey! Nipsey! Nipsey!"

At the beginning of the service, which lasted more than four hours, a montage of photos showing Hussle throughout his life was played on large screens inside the 21,000-seat arena, accompanied by a recording of Frank Sinatra's "My Way."

The British singer Marsha Ambrosias performed an emotional rendition of "Fly Like a Bird," while R&B singer Jhene Aiko sang "Eternal Sunshine."

Former President Barack Obama sent a letter that was read by Hussle's friend and business partner, Karen Civil. In the letter, Obama said he never met Hussle but "heard his music through my daughters" and learned of his community work in Los Angeles' Crenshaw District.

"After his passing, I had the chance to learn more about his transformation and his community work," Obama wrote. "While most folks look at the Crenshaw neighborhood where he grew up and only see gangs, bullets and despair, Nipsey saw potential. He saw hope. He saw a community that even through its flaws taught him to always keep going."

"He set an example for young people to follow and his is a legacy worth celebration," the letter continued. "I hope his memory inspires more good work in Crenshaw and communities like it."

Minister Louis Farrakhan, leader of the Nation of Islam, told mourners that Hussle's given name at birth, Ermias, means "God is rising" in Eritrean.

"He lived the gang life but he didn't stay there," Farrakhan said. "He lived the life of the hood but he rose above the pull of gravity."

Actress Lauren London, Hussle's girlfriend and the mother of the youngest of his two children, 2-year-old Kross, moved mourners to tears by sharing a text message she wrote to Hussle on Jan. 21, which read in part, "You've made me into more of a woman, you've given me the opportunity to really love a man . You've been with me when I've been sick, through all my fears. You have encouraged me and inspired me to reach higher."

Snoop Dogg said he and Hussle had so much in common that when they first met it was "like a magnet coming together." He said Hussle was a "peace advocate" and he thanked his mother and father for "giving us Nipsey."

Legendary singer Stevie Wonder told the crowd that he had looked forward to watching Hussle's "wonderful life" unfold only to have it end too soon.

"It is a heartbreak to lose a member of our family. It is a heartbreak because it's so unnecessary," the 68-year-old Wonder said. "We still are living in a time where ego, anger, jealousy is controlling our lives. It is so painful to know that we don't have enough people taking a position that says, 'Listen, we must have stronger gun laws.' It's unacceptable."

Before singing one of Hussle's favorite songs, "Rocket Love," and the Eric Clapton ballad "Tears in Heaven," Wonder recalled how Hussle motivated and inspired people everywhere he went.

"I hope that he motivated you enough to say, 'Listen, enough of people being killed by guns and violence,'" Wonder said.

The memorial service was followed by a 25-mile funeral procession to Hussle's final resting place, Forest Lawn Memorial Park. The cortège was expected to travel through Los Angeles' Crenshaw District, where Hussle grew up and was shot to death in front of his clothing store, The Marathon.

Tens of thousands of fans lined the procession route, which was to go past the intersection of Crenshaw Boulevard and West Slauson Avenue. Earlier this week, Los Angeles City Councilman Marqueece Harris-Dawson announced that the intersection would be renamed "Ermias Nipsey Hussle Asghedom Square," a move that was prompted by a petition signed by more than 500,000 people.

"Nipsey's genuine nature allowed him to be a light to everyone he interacted with from family, friends, fans, and his larger community," Harris-Dawson, who represents the South Los Angeles neighborhood, said in a statement.

Hussle had invested heavily in the Crenshaw District, opening several businesses and employing people from the community.

"As a father, brother, and son, Nipsey was a rock helping to build an empire that will continue through generations," Harris-Dawson said in his statement. "Nipsey will always be remembered for delivering a pure, authentic Los Angeles sound, his numerous philanthropic efforts, his innovative, community-focused business mindset, and his humble heart."

Hussle, who had spoken publicly about his involvement as a youth with the Rollin 60s gang, one of the biggest Crips gangs in Los Angeles, had scheduled a meeting with Los Angeles Police Chief Michel Moore to discuss how he could assist the LAPD with its programs to help underserved children and to keep kids out of gangs, Steve Soboroff, president of the Los Angeles Police Commission, told ABC News.

Two days before he was scheduled to meet with Chief Moore, Hussle was gunned down outside The Marathon allegedly by a man he had a personal dispute with, police said. Two men standing near Hussle also were shot but survived.

The alleged gunman, Eric Holder, 29, arrested after a two-day manhunt, was charged with one count of murder, two counts of attempted murder and one count of possession of a firearm by a felon in connection with the shooting, the Los Angeles County District Attorney's Office said in a statement.

Holder's attorney, Christopher Darden, entered a not guilty plea on his behalf at his arraignment last week. Holder is being held on $5 million bail and faces up to life in prison if convicted.

Police used surveillance video and social media posts by witnesses to help identify Holder as the alleged gunman who shot Hussle, officials said.

ABC News' Deena Zaru contributed to this report.