Joe Perry of Aerosmith is and has been cool for at least four decades. He wouldn't trade his musical talent, life experiences, health reports, wardrobe or bank accounts with the entire staff of Ultimate Classic Rock. We're perfectly clear on all of that, and still we need to say this: Joe Perry's new mustache is kind of a head-scratcher.

Look, don't take our word for it. Just look at how hard the legendary guitarist's longtime friend and musical partner, Steven Tyler, is biting his tongue trying not to laugh at him in this photograph, taken today (Nov. 5) at the band's triumphant free street concert in their hometown of Boston, Mass.

Think about this for a second -- these two have been to hell and back together, battling long odds and drug addiction to build, destroy and rebuild an empire most of us could never dream of. Yet somehow the singer, who is never without exactly the perfect quote for any situation, can't talk Perry into either cutting those two caterpillars off his face or growing in the final third of a proper mustache?