"It's important we support our defenders. It's a very serious time in our country and the world," he said.
About 1,800 turned out Saturday to watch the band, a spinoff of Sinise's role in "Forrest Gump."
"I just want to see what Lt. Dan is doing now. See if they're any good," said Sgt. Erik Bull.
"I think they're actually surprised when they hear the band," Sinise said. "I don't think they expect very much."