Baez had been invited by rocker John Mellencamp to join him at a Friday performance for soldiers recovering at the hospital. But in a letter in the Wednesday edition of The Washington Post, Baez said she was dis-invited by Army officials.
"I have always been an advocate for non-violence," she wrote, "and I have stood as firmly against the Iraq war as I did the Vietnam War 40 years ago. ... I realize now that I might have contributed to a better welcome home for those soldiers fresh from Vietnam. Maybe that's why I didn't hesitate to accept the invitation to sing for those returning from Iraq and Afghanistan.
"In the end, four days before the concert, I was not 'approved' by the Army to take part. Strange irony."
Baez said she wasn't told why.
Walter Reed officials did not respond to several requests for comment, the Post said. However, the newspaper said spokesman Steve Sanderson told another publication that requests by Baez and newsman Dan Rather to participate were too late to be accommodated.