Woman thinks she was singing on an empty train -- but someone was watching

Should she try to sing some more?

Fans of the band Chicago know the next line and that it refers to time: “25 or 6 to 4.”

A woman on a Chicago Transit Authority train had plenty of time on her hands, so she decided to record herself after she stepped onto a seemingly empty car, WGN reported.

“Stevie” filmed herself singing on the train, bouncing along the car as she belted out the line “Nobody in this seat, I’ll put my butt in the seat ’cause it’s juuust me.”

Then the woman realizes she is not alone.

"Oh, my God, I realized there's another person on the train," she ad-libs.
One of Stevie's friends tweeted the video of her song, along with her reaction when she realizes she had an audience.