Denise Richards wants you to know that theres a very good reason she sang Take Me Out to the Ballgame the other day at a Chicago Cubs game. And, unlike other onscreen vixens like Leighton Meester, it certainly has nothing to do with her trying to impress people with her singing abilities. The E reality star knows she cannot carry a tune, but... Richards was in the Windy City for a fundraiser for the Kidney Cancer Association (her mom died of the disease about a year ago). While she was there, Richards asked Cubs management if the group could set up an informational booth at Wrigley Field during Fridays game. In return, they said, 'Will you sing? Richards explains to me. So I said yes, because its for a good cause and we want to raise awareness about kidney cancer. -E Online Unfortunately, the cancer message got lost along the way, because as soon as video of Richards performance hit the Internet, the trashing began. Im clearly not a singer, she says. I wasnt doing it to show off my pipes. Thank God I wasnt singing the national anthem. But I thought it would be fun...I had no idea the backlash I would get. As for her critics, Richards said they need not worry about her ever singing in public again. It took everything in me to get up there and do that, says Richards. My dad and my sister kept saying, 'Just remember youre doing this for Mom, so thats how I got through it. Its just unfortunate that doing something good was turned into such a negative. No word yet if the singing will be included in Richards reality show. The second season premieres June 7.