As millions across the world watched on TV, more 17,000 of Michael Jackson's fans, family members, and friends gathered to pay their respects to the King of Pop today during a public memorial service at Los Angeles' Staples Center.

But one "goodbye" stood out among the rest.

While working in a Miami studio with Cool & Dre -- who produced a number of tracks on his band's new album, The Quilt -- Gym Class Heroes frontman stumbled across a YouTube favorite, thanks to a tip from Cool.