The atmosphere on Zu’s new album is coarse. Synth and saxophone textures bleed so well with the rhythm section that they become indistinguishable from each other. The sound contrasts with the overall pillowing ambience, creating a looming sense of impending rain throughout. Form start to finish, Ferrum Sidereum makes for a mordant double album that lacerates its listeners with rough textures and unpredictable grooves.
Ferrum Sidereum (Latin for “cosmic iron”) is comprised mostly of sharp sax textures and brittle, treble-dominant drum production that contribute to an overall acerbic sound. For such an epic and sonically-confrontational project, there is far less muddiness and chugging than you might anticipate. Rather, this is a sharp, shapeshifting collage of diverse dynamics which boldly slice through the mix.
The berating toms on tracks like ‘Kether’ radiate a sense of driving and morphing rhythm that seem deep-rooted within the band’s rhythmic core. A unique sense of synchronicity between the three instrumentalists is tight and palpable throughout. Opening track, ‘Charagma’ boasts this sense of uniform dynamic versatility. Luca Mai switches seamlessly from rash bursts of saxophone to clear and cushioning synth ambience. The third track, ‘Kether’ is texturally writhing, fuelled by brittle toms and razor-sharp bass textures. The seventh track, ‘Fuoco Saturnio’, opens with a rounded, arpeggiated chord progression which, accompanied by swelling synths, creates a beautiful, simmering atmosphere that precedes a sudden launch into more abrasive chugging.
As the album progresses, new textures arise in contrast with the previous tracks, keeping the sprawling 80-minute runtime unpredictable and intense. ‘The Celestial Bull and the White Lady’ opens with jagged, almost 8-bit-sounding synth notes which wouldn’t sound out of place on the original DOOM videogame soundtrack. These synthetic textures oscillate and drone into grand swells as the track builds, before bursting into a unified climax of marching, warlike attrition.
It’s the closing title track that arguably provides the most poignant example of the band’s instrumental craftsmanship. Synth and saxophonic textures mesh together like woven silk. Following a sea of dark ambience, a sudden cluster of irregular and off-beat chunks of rhythm ambushes the mix, creating a start-stop climax that never resolves itself. This double album is sprawling and cathartic without relying on industrial heaviness. After a quarter-century as a band and over a dozen albums, Zu have acquired a natural, almost spiritual intensity.
