Just moments after paying tribute to pop icon Michael Jackson at Tuesday's public memorial service Mariah Carey took to her Twitter page to critique her emotional performance of 'I'll Be There.'

"Sorry that I wasn't able to pull it together and really do it right, " she twittered. "But I was literally choked up when I saw him there in front of me." The 39-year-old was the first performer to sing during the event held at the Staples Center Tuesday.

Taking the stage alongside collaborator Trey Lorenz, Carey, fell off key in the very beginning of her performance but quickly pulled it together. "Trying to sing today was basically impossible for me. I could barely keep myself from crying," she said.

Carey chronicled her day via Twitter and wrote a tribute to the late King of Pop. "He inspired with his timeless music. He will be forever in our hearts."

Although originally released by the Jackson 5 in 1970, Carey remade the song on her 1992 released MTV Unplugged album.

Actress Brooke Shields, singers Jennifer Hudson, Smokey Robinson, Stevie Wonder and Usher -- who broke down following his emotional performance of Jackson's 'Gone To Soon' -- and Shaheen Jafargholi of 'Britain's Got Talent' took the stage after Carey to say goodbye to Jackson.

In other Carey news, the r&b diva is set to release her 12th studio album, 'Memoirs of an Imperfect Angel,' on August 25.