Sweden's Tiamat displayed an incredible learning curve in the year after their debut, resulting in 1991's excellent The Astral Sleep.
Short synthesizer instrumentals ("Neon Aeon" and "The Seal") open and close the album, setting the stage for the band's new ability to incorporate background keyboard textures (often resembling angelic choirs) to even their most aggressive death metal.
Vocalist Johan Edlund has already begun transforming his grunt into a raspy growl (actual singing would follow), and his songwriting is original and diversified on standouts like "Mountain of Doom," "Lady Temptress," and the multifaceted "A Winter Shadow." Acoustic guitar precipitates the otherwise furious "On Golden Wings" and "The Southernmost Voyage" (another highlight) and the band finally thrashes out a bit on "Ancient Entity" and "I Am the King (Of Dreams).".