"Check one, two," Luda said into the mic.

"Play 'Stand Up,' " he told his DJ during soundcheck. Luda was very normal and businesslike as he paced with his hand in his pocket while going over his bars.

"Turn it down a little," the Grammy winner directed. "On the monitor, not the vocals. That's perfect. So do it from the top? Good.

Read more and check out photos from the rehearsal after the jump.

"Could we make sure it doesn't feedback as I'm walking through here?" he asked as he made his way to the place where he plans to make a surprise entrance.

After the engineers took care of technical matters for a few minutes, Luda -- who couldn't see anyone from his vantage point -- reminded everyone it was time to rock.

"I'm ready when you guys are. Are you waiting on me?" he said very humbly.

The DJ cued up "Move," and 'Cris began his rap as he strolled to his place in front of the DJ booth. While making a transition to the next track, his DJ missed the cue.

"You gotta be a little bit tighter, bruh," Cris said with a grin, before actually pressing some buttons by the turntables himself.

"All the vets, we love you," Luda said as he closed out. "Did somebody time that?"

During his second walk-through, 'Cris and company were a lot tighter and actually were just seconds shy of their allotted time. After a short talk with the MTV crew, Luda contemplated switching up his lineup some -- obviously a great set will be no problem. This is a guy who can go 90 minutes easy and still not run out of cherished hits.

Ludacris is one of the many stars that will take to the spotlight during "A Night for Vets: An MTV Concert for the BRAVE." The show, which also includes performances and appearances by Beyoncé, Kanye West, 50 Cent, Kid Rock, Fall Out Boy and Will Ferrell, is an event organized to inform and promote backing of the Bill of Rights for American Veterans (BRAVE), a petition presented by MTV and several veterans' organizations. The concert airs on October 24, at 8 p.m. ET on MTV.