Justin Timberlake Retires 'SexyBack,' Rocks With 50 Cent At Las Vegas Concert

Rihanna, Jonas Brothers, Leona Lewis join Timberlake at benefit for Shriners Hospitals for Children.

Justin Timberlake brought a star-studded lineup to his "Justin Timberlake and Friends: A Special Evening Benefiting the

Shriners Hospitals for Children" concert at Planet Hollywood in Las Vegas on Friday. 50 Cent, Rihanna, the Jonas Brothers, Leona Lewis, Will.I.Am, Maroon 5's Adam Levine, Boyz II Men and Lionel Richie graced the stage with him.

The evening's highlights included Timberlake dueting with Levine, the two of them performing with 50 Cent, and Timberlake teaming up with Will.I.Am and Richie for the Commodores' hit "Easy," according to

StarPulse.com. Will.I.Am also joined Timberlake onstage.

"We sent letters," Timberlake told MTV News about how he secured such a strong lineup. "We had to go through publicists, but we sent letters. I actually had more responses than we were able to use. [For] the event we got like everybody and their mother on the list. It's a great, great organization. They've helped so many kids, even over the last year. So that's what we're doing. We're rocking out for the kids."

Timberlake — who also held a golf tournament supporting the organization — admitted he's already lining up guests for next year's concert.

Timberlake officially "retired" his 2006 hit "SexyBack" at Friday's show, and also told MTV News that he's focusing on working with other artists, rather than his solo career, for the time being.

"As far as myself I don't have that ... I could change [my mind] next week, but I don't have the bug to jump in and start the whole process again, and

touring again. I do love it, but it's tiring," he admitted.

In addition to his recent work with Madonna and T.I., he also talked about tracks he recorded with Rihanna. "[Recently] I worked with Rihanna, hopefully working on her next record," he said. "She's on a roll. I think she sort of has something different to offer. You can use her voice as a template for many different styles. She has a keen fashion sense and on top of that she's hot. Whatever it is, she's got it."

However, he declined to get into details about who else he's been working with. "I've been working with different people here or there," he said. "I feel weird. You'll hear it when it comes out. I would love to give you everyone but there's some stuff that might not work out due to business stuff, unfortunately.

"I'm going to go pimp myself to Leona Lewis, 'cause I think she's an amazing singer!" he offered, then gave a joking offer to artists: "Give me a buzz! Just call me. I got beats, too," he laughed.