The 1979 album "Blå Vardag" by ATLAS is in every way indispensable when looking at the progressive music history of Sweden. Their sole debut album is combining the almost Zamla -esque playfulness on tracks such as "På Gata" with intricate, mellow melodies on e.g. "Blå Vardag" and "Den Vita Tranans Väg" while infusing heavy organs, carefully refined guitar riffs and fantastic synthesized sound scapes.
If you have any interest in instrumental 70's prog (and even the RIO scene), you're in for a real treat - this album is not to be overlooked!