Someone else recommended Vintersorg. It's now on my list of bands to check out, along with many others from this thread.

But while we're on the topic of Swedish artists (who have unrelated day jobs†), I absolutely have to mention Seventh Wonder[0].

They based their 30-minute anthem "The Great Escape" on Aniara[1], an epic sci-fi poetic cycle authored by Harry Mattison. It's a significant piece of literature because, to quote his Wikipedia page[2]:

"He was awarded a joint Nobel Prize in Literature in 1974 together with fellow Swede Eyvind Johnson 'for writings that catch the dewdrop and reflect the cosmos'."

Someone actually uploaded a comparison of lines from the English translation of the poem to the lyrics of the song[3]. Maybe I'll write a more detailed article about this at some point, but it's a beautiful song that really lets you get into the story.

[0]: https://en.wikipedia.org/wiki/Seventh_Wonder

[1]: https://en.wikipedia.org/wiki/Aniara_(opera)

[2]: https://en.wikipedia.org/wiki/Harry_Martinson

[3]: https://docs.google.com/document/d/1MUd4hf0FH4gQQN_9kypNtGBe...

† Tommy Karevik is the singer in Seventh Wonder (and Kamelot) and also plays the part of the Prodigy in Ayreon's Theory of Everything. He is also a firefighter.