> Listening to your favorite new song everyday for a week is spaced repetition and very enjoyable, no pain whatsoever.

That's not really SRS though; a key part of SRS is the heuristic for when you next get exposed to the thing you're trying to remember based on your previous "got it"/"missed it" response. I suppose "every day" is one such heuristic, but it's not really in the spirit of SRS.

And you're mixing up enjoying the content with the mechanics of an SRS system.

That's a good example of an exceptional case. It is a good result to know. But really the learning-science is concerned about how to make learning so enjoyable that you are willing to do it. However the case of learning your favorite tune does not help much with the general question of what techniques you should use when trying to learn something else than your favorite tune :-)

This relates to learning as much as watching some coding streams on Twitch to an actual coding.