Having a saxophone alongside heavy music has been a staple ever since King Crimson's "21st Century Schizoid Man" became the heaviest song of the 60s (arguable, but a respectable pick), all building upon the heaviness of free jazz giants like Ornette Coleman, Eric Dolphy, or Peter Brötzmann. Ever since we've had both metal bands employing a saxophone as part of their soundscape, as well as jazz bands who bridged the gap into punk and metal, like Naked City, Shining (NOR), Ex Eye, and the very recent example of Neptunian Maximalism. Of course having a saxophone doesn't immediately equate to jazz, and there may come a point where having a saxophone in your metal song can come across as overly saturated trend hopping, but a lot if not most of the interbreeding between jazz and heavy music has used the saxophone as a focal point.
Enter Zu, an Italian trio consisting of drums, bass, and saxophone, about as jazz as you can imagine a trio being. Debuting in 1999 with Bromio, a jazz album whose punk heaviness had less to do with metal and more with heavier prog movements of the time like math rock a la Polvo or brutal prog a la Ruins. Over the course of their career, they played around with a lot of genres, collaborated with the likes of Current 93, Oxbow's Eugene Robinson, and Mats Gustafsson among others, with their most overtly metallic records in the form of 2009's Carboniferous and 2015's Cortar Todo, the latter of which was their last heavy record for a while, the band embarking in various kinds of mellower experimental explorations since, so Ferrum Sidereum not only arrives after a seven years release drought for Zu following 2019's Terminalia Amazonia, but also more than a decade since they've been a heavy band on record.
Ferrum Sidereum thus attempts to make up for it, with roughly 80 minutes of material, making it quite a behemoth of an album, something that is quite fitting for albums of this kind. The album is pretty even in flow, all but one interlude aside being songs in the 5-10 minutes range, making the band feel very focused about the kind of songs they wanted to deliver on this record, which is very groovy, very dense, and very heavy jazz metal. Even compared to Carboniferous and Cortar Todo, Ferrum Sidereum feels like the most overtly metallic of Zu's albums in a way that tones down their experimental tendencies, a glitchy breakdown in "A.I. Hivemind" aside, in favor of sharpness and focus on this groovy, dense, heavy sound.
The denseness of it owes a lot to producer Marc Urselli making the sound feel huge and full without it feeling overbearing or cacophonic. For such a long instrumental album, Ferrum Sidereum isn't necessarily a background listening kind due to its heaviness and head-bopping grooves, but it isn't hard on the ears either. The bass especially is mixed incredibly well, having to compensate for the lack of guitar with its distortion being what the album owes a lot of its heaviness to, and some of its grooves being not that far off something you'd hear in a lot of Tool worship bands. There are plenty of dynamics too, from soundscapes additions either in the form of acoustic string or electronica that feels in line with their more recent explorations of the kind, making the 80 minutes feel like more of a breeze than expected.
Perhaps metal is not stored in the guitars after all.
