Mitt Romney has battled the perception that he’s just not very cool, and vice presidential candidate Paul Ryan took the opportunity to make a gentle joke at his expense that played on that perception.

“We’re a full generation apart, Governor Romney and I.  And, in some ways, we’re a little different,” Ryan said at the Republican National Convention today.  “There are the songs on his iPod, which I’ve heard on the campaign bus and on many hotel elevators. He actually urged me to play some of these songs at campaign rallies.  I said, I hope it’s not a deal-breaker Mitt, but my playlist starts with AC/DC, and it ends with Zeppelin.”

Ryan used the joke to emphasize Romney’s argument that he’s turn-around artist who can fix the economy. “A generation apart,” he said. “That makes us different, but not in any of the things that matter.  Mitt Romney and I both grew up in the heartland, and we know what places like Wisconsin and Michigan look like when times are good, when people are working, when families are doing more than just getting by.  And we both know it can be that way again.”