The original program for Thursday's ceremony had Christie's remarks followed by Idina Menzel's performance of the song. That sent social media aflutter with speculation that the scheduling was a jab at the governor over accusations that his staff intentionally clogged traffic near the George Washington Bridge to punish a political adversary.
But just before the ceremony, museum spokesman Anthony Guido announced that Menzel, star of the Broadway show "If/Then," was sick and would not perform. In her place, another member of the show's cast, LaChanze, herself a 9/11 widow, performed "Amazing Grace."
Guido said the change had nothing to do with Christie or the song.
A spokesman for "If/Then," Tom D'Ambrosio, said Menzel has a cold and had to pull out of Wednesday night's performance at intermission. He said she was scheduled to perform Thursday night.
Christie spokesman Kevin Roberts declined to comment.
AP writers Mark Kennedy and Angela Delli Santi contributed to this report.