Songfacts®:

• Agnetha Fältskog takes lead vocals on this song about a divorced couple who share custody of their son, Dan. Their child can be difficult to control, so as she hands Dan over, she tells her ex to "keep an eye on" him.
• This is one of ABBA's Bjorn Ulvaeus and Benny Andersson's story songs like "Fernando," "Chiquitita," "The Day Before You Came" and "Don't Shut Me Down."
• The four ABBA members that recorded this song comprise two divorced couples. While Benny Andersson and Frida Lyngstad didn't have children together, Bjorn Ulvaeus and Agnetha Fältskog had a son, Peter, and daughter, Linda. We can surmise that Bjorn drew on his personal experience sharing custody for the lyrics. For Agnetha's vocals, she likely harked back to her feelings about missing her children when it was Bjorn's turn to have them.
• Ulvaeus' lyrics are a fresh perspective on the breakup song. "All of us who have been divorced know what it's like to leave that little kid and seeing how absorbed that little kid is with the other parent," he told Apple Music. "And he waves, or she, and you stand there and you feel, 'Argh.' I find it interesting to explore things that happen in relationships that haven't been explored before. I don't think that this has."
• Throughout Voyage, Ulvaeus and Andersson insert references to older ABBA songs. "Keep an Eye on Dan," for instance, closes with the same piano melody that opens "S.O.S."