Over the years, Therion has seen many line-up changes, resulting in the presence of rhythm guitarist and former vocalist Christofer Johnsson as the only constant in the band. For the most part, the band has not been defined by their continuing changing line-ups, but by their ability to musically evolve. However, their last line-up had some of the best musicians, notably guitarist Kristian Niemann and clean vocalist Mats Levén. These two musicians are no longer with Therion, which leaves the question of whether or not the band is as good as it used to be.
In the case of Kristian Niemann, his guitar skills were almost unrivaled, as he shredded with an impressive degree of speed and precision. On Sitra Ahra, he has been replaced by Christian Vidal, who like Johnsson, is competent, but not a guitar god. As for the vocals, Levén was a versatile singer that could do everything between heavy metal, and duet with the operatic soprano vocalist. On the new album, he has been replaced by Thomas Vikstrom. The new singer, unfortunately, has a bad voice, and gives the music a cheesy sound.
The rest of the album has a lot of what is to be expected from Therion. The choir has a large role, the sound ranges from dark to fast heavy metal, and Lori Lewis once again impresses with her beautiful classical vocals. Her high point is in Unguentum Sabbati, which pays a very noticeable homage to Andrew Lloyd Weber's The Phantom of the Opera. The low point of the album is on Hellequin. This song is everything that is wrong with Therion. It is overproduced, and attempted to cram in every existing vocal style, making the song a complete mess. The rest of the album embraced a lot of the world music sound and instruments that are not associated with the heavy metal sound, further broadening Therion's sound. The ten and half minute Land of Canaan showed this musical diversity in its movements, and it ended with some of the best vocal layering the band has ever done. However, there are a couple of additional misses such as the children's choir which came off as tacky, and Snowy Shaw's death metal style of vocals just not being a suitable replacement for Johnsson's voice. Overall, Sitra Ahra is a decent album, but is only recommended for fans of the band.