 The album opens out with 'Howl', a grinding, but graceful opener. The song starts with an opening two minutes of intense and spacious drone synthesisers. The following two minutes of the song break into "unrelenting and brutal" mathcore with Eva Spence making her vocal debut with her "gleefully guttural vocal register". The song is used as an example of how the band is using more complex, but 'more rewarding' song structures in their music. ‘ Ex Luna Scientia ’, the opening single for the album is seen as a more expansive and more melodic song in comparison to their previous work, placing emphasis on Eva Spence ’ s singing rather than her trademark 'guttural' style. Rock Sound reviewer Oliver Robertson used the song as an example for the sonic development of the album as it is "more focused on making each element stand out now, rather than creating simply a cacophony of noise." The introduction to 'Empiresk' is seen as being "completely caked in reverb" and ends with a stoner riff. The "sparse piano chords" that open both 'Empiresk' and 'Prelude II', among the atmospheric breaks that are featured on other tracks on the album defy the aggression featured on the rest of Astraea. Songs like 'The Scales of Balance', 'Remancer' and 'Gloam' are seen as having a fimiliar style to the Rolo Tomassi's previous work.' Gloam ', specifically the last half of the song, showcases a "battle between melodic keyboard [s] and screamed vocals with a real sense of urgency and threat."' Remancer'specifically has been considered as almost like Mastodon. The album closes with' Illuminare ', a song which Metal Hammer reviewer Merlin Alderslade cites as showing Radiohead and Sigur Rós influences.
