Yes is that the one, I recall where Anderson and Duchnovny were investigating a UFO sighting by Homer. In the end they were joined by Leonard Nimoy and they sang “Good Morning Starshine”.
I remember! *laugh* Who’d have ever thought that Nimoy could carry a tune? *grin*
Anderson and Duchovny have trouble remembering the finale -and much laughter results!
https://www.youtube.com/watch?v=GLwJjlmj0go