If you want to sing the National Anthem

For you aspiring Wrigley Field National Anthem singers, please follow the following procedure, found on the Cubs website:

National Anthem: Any person(s) wanting to perform the National Anthem prior to a Cubs game must submit a video tape of the singer(s) performing an "a cappella" version of the National Anthem. Mail tapes to: National Anthem, Chicago Cubs, Wrigley Field, 1060 West Addison Street, Chicago, Illinois 60613. For more information, call (773) 404-CUBS. Please be aware that tapes will not be returned.

Apparently the Cubs are not concerned about if the anthem is "accompanied" or not.