Luke Bryan catches heat for anthem performance.

Luke Bryan apologized Wednesday for having written down some words to the National Anthem on his hand before performing it at the Major League Baseball all-star game the night before in Kansas City.

Bryan received criticism for doing so but he defended himself via Twitter.

“I had a few keys words written down to insure myself that I wouldn’t mess up. I just wanted to do my best. I promise it was from the heart,” he Tweeted.

Bryan later said, “If I offended anyone with my approach I sincerely apologize. Anytime I sing the anthem it is an honor and my heart beats out of my chest.”

Bryan also received flak for checking his watch during the Anthem. He Tweeted, “I did check my watch because I knew the stealth bomber would fly over 2 minutes in and I knew a started a little late,” he wrote.