Justin Bieber was chosen to sing the first line of “We Are the World.”

The reworked rendition of the 1985 chart-topper meant a cavalcade of stars coming together tonight at the Jim Henson Recording studio in Hollywood, where the 15-year-old Canadian sensation was in awe of his older colleagues, among them Barbra Streisand, Akon, Harry Connick, Jr., Pink, and dozens of others — all there to lend their voices to support Haiti relief.

But it was Celine Dion who Justin first responded to.

During the session of the redo of the Michael Jackson/Lionel Ritchie blockbuster song to help Africa, Beiber tweeted: “Singing We Are The World right now with Celine Dion next to me!! Everyone is here!! I’m meeting everyone!! This is insane! Ok ok chill”.

Joel Madden also took to the keyboard to discuss his feelings about the amazing night among the 75 luminaries, including Nicole Ritchie and their daughter Harlow. The Good Charlotte band member tweeted a bunch of thoughts:

“We are the world was great. Nice work Lionel, Quincy, and RedOne. Highlights: Kanye hanging with Harlow, and meeting Daft Punk.”

“More highlights: Carlos Santana and Brian Wilson singing next to me. Among many many others. Everyone was really cool today.”

“Also @Pink needs to watch out cause harlow was flirting with @hartluck she really warmed up to him. She was asking for him when we left.”

Jordin Sparks, also overcome by the incredible musical event, tweeted:

“Being apart of the We Are The World remake is such an honor. So much talent together for a great cause. I will never forget tonight.”