What makes The Astral Sleep by Tiamat notable?

'The Astral Sleep' is significant for its role in establishing Tiamat as pioneers of gothic metal, influencing numerous bands in the genre. The album received positive critical reception and helped solidify the band's place in the early '90s metal scene, leading to greater recognition and commercial opportunities. Released in 1991, 'The Astral Sleep' was Tiamat's second album, following their debut 'Sumerian Cry.' At this point, the band began to carve out their distinct identity within the gothic metal genre, moving away from their earlier death metal roots and embracing a more atmospheric sound.