Billy was at Wrigley Field on Friday and threw out the ceremonial first pitch and sang the 7th Inning Street.

We have uploaded the video (thanks Veji) for you watch.

Many thanks to Karen for this image from the Chicago Sun Times.

The Official Chicago Cubs twitter feed posted this image:

Actor William Petersen listened to Brian Simpson sing the National Anthem, then sang today's stretch in the booth: http://t.co/fQzKMniE
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