I think Enola Gay by Orchestral Manoeuvres In The Dark is a perfect example.

It sounds upbeat and fun but it’s about the atomic bomb dropped on Hiroshima.

Some of the lyrics are incredibly powerful and I still get chills when I hear it.

I remember liking that video the first time I saw it. If I remember correctly though, the creator of that video had quite a few sexual abuse allegations against him and I wasn’t really into it after that came to light.