Being tough is a necessary part of being one of the judges on Fox's American Idol. The Grammy and Emmy-winning artist Harry Connick Jr. has now joined new Season 13 of the reality-singing competition series, where he has earned his nicknames "Harsh Harry" and "Hatchet Harry."

"If this were a football game, you lost this game," he says to the contestants during the notoriously challenging Hollywood Week rounds. "Technically, all four of you should be cut." Connick Jr. also criticizes one group's harmonies, saying he wishes they sang in unison because they were "all out of tune anyway."

However, he explains being honest and real is an essential part of his job on the series. "Sometimes you do have to give bad news," says Harry Connick Jr. "Sometimes that's the best thing that these kids can hear is the truth. In fact, at all times that's the best thing they can hear ... And I would want to be told or I would want my friends or children to be told the absolute truth. I think you can be diplomatic about it, but you also have to be real. You have to tell it like it is. There was one group that came out yesterday that I thought was horrible ... and I said, 'that was terrible. I couldn't wait for it to end.'"

He then discusses how he has learned from brutal honesty. "As a kid, when my teachers would critique me and it happened every day for years and years and years," says Connick Jr. "You develop a tolerance for it, especially when it's right and when it's sincere and when it helps you. Nowadays, if I do something wrong and there's somebody that I know and love says, 'Hey man, that was a mistake,' I'm at the point of my life when I can admit it almost immediately."

American Idol Season 13 is slated to air on Wednesday, Jan. 15, at 8/7c on Fox.