She hit the high F, held it, then blew out a breath and turned to look back at the band — a quick, disbelieving glance toward her musical director. Some 30,000 people read it before they had finished screaming: Celine Dion did it.

It was "All By Myself," the song the Quebec superstar's voice has been measured against since 1996, saved for the encore of her first full concert in more than six years — her first since stiff person syndrome, a rare, progressive neurological disease, attacked her muscles, including those of the throat.