The song "Chicago Line" by John Mayall's Bluesbreakers is about a man who is waiting for his lover to return on a train from Chicago. He's not sure if she'll actually come back and he's been checking the train schedules every day. It's apparent that she has left him for someone else, as the lyrics mention "She got another mule kicking in the stall". The man is heartbroken and reminiscing about the good times they had together. The song ultimately speaks to the pain of lost love and the difficulty of moving on.
