Pat Benatar's "Invincible" -- a Top 10 hit that was the theme song for The Legend of Billie Jean as well as the lead single from Benatar's Seven the Hard Way album -- turns 40 this year. But the song's greatest significance for the singer may have come 16 years after its release. Benatar and husband Neil Giraldo and their band were scheduled to perform at an outdoor venue in California’s Napa Valley on Sept. 11, 2001, the day of airplane terrorist attacks in New York City and Washington, D.C. "I was literally having a heart attack," Benatar recalls to...