Strange but true: Country superstars Rascal Flatts jammed with Hollywood star Gary Sinise (CSI: NY, Forrest Gump) Tuesday night (March 6) in Nashville.

Turns out Gary plays a pretty mean bass, and he's in a group he formed called Lt. Dan Band.

So country legend Charlie Daniels asked the actor to come join him for a fundraiser for military veterans in Nashville's Allen Arena.

What the crowd didn't know was that Rascal Flatts was the special guest. And the crowd went wild!

Then again, the Rascal Flatts guys were pretty jazzed to meet Gary Sinise. The guys were so excited that Flatts' Jay DeMarcus posted a pic on Twitter with the caption, “Great night.”