For as long as I can remember, I've done this for pop songs. They pack so much emotion into 3 or 4 minutes, but not a lot of detail. I heard an old song today that reminded me of this, because sometimes the headcanon takes over the reality. In all my desire for a happy ending, I forgot that Dave Loggins' Please Come To Boston doesn't end with him going back to Tennessee like he really, seriously, oughta.
Other times the headcanon is just me imagining specific people (real or fictional) as the protagonist of the song. Tom Petty's I Won't Back Down came out around the same time as some other stirring world events, and the two are linked in my head. On a lighter note, I can't help but thinking about fictional Al & Peg Bundy whenever Meatloaf's Paradise by the Dashboard Light is on the radio. More recently, I realized that that the lyrics to that silly "cups" song is actually the perfect accompaniment to Clara Oswald's departure from Doctor Who last year... even including the "long way round."
Sometimes the stories from songs and TV shows are explicitly intertwined. I'm sure virtually nobody will remember Christopher Cross' Swept Away, but it always makes me wonder whether, after the final episode of Growing Pains, Mike Seaver eventually fell out with whats-her-name and got on a plane back to Hawaii.
Then there are the ones that I'm convinced have some secret backstory, but I don't know what it is. Do you know there are 2 seemingly unconnected songs, released 11 years apart by completely different artists, that both: (1) mention the River Seine in France, (2) are sung in an admonishing way to a listener who better stop doing something bad, or else, and (3) are positioned as the second to last track on the B side of their respective albums. So, were Billy Joel ("Somewhere Along the Line") and Don Henley ("Drivin' with Your Eyes Closed") sending out a coordinated message to the same person, across the years?!
There are some songs, of course, into which I have to put myself as the protagonist, but no need to mention those.
