It appears likely that this clip was shot in 1984, the last time the Cubs were really favored to go to the World Series (knock on wood), and performed on a rooftop just outside the left field bleachers (Waveland Avenue, as mentioned in the song).

The song is particularly poignant when you realize that Steve Goodman, writer of such tunes as "City of New Orleans" (made famous by Arlo Guthrie), "You Never Even Call Me By My Name," and "Go Cubs Go" (sung after every Cubs victory at Wrigley), was dying of leukemia in 1984.  He passed away four days before the Cubs clinched their first ever NL East pennant (back then, there were only two divisions, East and West), and was to sing the National Anthem at the first playoff game at Wrigley Field since 1945.

It's not just a good baseball song, but a good song in general.  Sure, it helps if you're a Cubs fan (who else would know who Keith Moreland is, and why he should "drop a routine fly"?), but if you've ever lived and died with a sports team, you'll hear something that resonates with you in "A Dying Cubs Fan's Last Request."

Go Cubs Go!

1

That is really awesome, and it's sad to know that he was dying when he sang it.

2 And the Cubbies crushed the hearts of their fans once again, getting creamed in their first post-season game.