The concert is part of a special tour to help in the fight against breast cancer.
Two fans will win the opportunity to join the group on stage.
It's a rock 'n' roll dream come true for a good cause. During its current tour, the legendary band Chicago is letting fans bid for a chance to sing with them-on stage. All proceeds go to the American Cancer Society's fight against breast cancer.
The idea came from Chicago's long-time manager, Peter Schivarelli, during a recent charity event.
"A woman was willing to pay a lot of money to come up and sing a song with us and donate it," said Schivarelli. "It kind of gave me the idea, this is something we could do, and we tried it with the Cancer Society for breast cancer."
"He brought it to us and we were on board immediately," said original Chicago band member Lee Loughnane. "To be able to give something back after all of these years of being able to do what I've done, basically since I was 11 years old, practice the trumpet... is great!"
"It's amazing to be a part of a group and go out there every night and have that legacy and see that you're helping on so many levels," said Chicago band member Jason Scheff.
These talented musicians understand how far-reaching and close to home breast cancer can be.
"It touches everybody - my mother is doing great; she caught hers in time, and my mother-in-law caught hers in time," said Scheff.
"My wife's grandmother had breast cancer many years ago,and she's a survivor," said Loughnane.
Chicago will perform Friday and Saturday night at Charter One Pavilion. The contest winner will sing the #1 hit "If You Leave Me Now".
"Every audience that we've played for, someone in the front row says, thank you very much for what you're doing," said Loughnane.
For more information, you can go to the American Cancer Society's "Sing with Chicago" website.