The latest from the uncompromising John McCowen is a split release between Dinzu Artefacts and Astral Spirits. Models of Duration follows the same trajectory as McCowen’s other amazing solo releases – Solo Contra (International Anthem, 2017), 4 Chairs in 3 Dimensons (Astral Spirits, 2018), Mundanas I – V (Editions Wandelweiser, 2018) but is also a whole world beyond those. McCowen continues to focus on extended possibilities of the clarinet family as well as acoustic phenomena (as with all his previous releases, there is no amplification or electronically generated sounds here) and it all shines through more dramatically than ever on Models of Duration. “Duration I” & “Duration II” bookend the record with similarly sustained and rhythmic drones that prepare us for what is to come & also bring us back into the real world at the end of the record. “Foggd” and “Hoskin” both traverse new levels of intensity that McCowen hasn’t hit before. Just when you get settled into any of the four tracks on the album and think you know what’s coming next, McCowen subtly shifts tones and sounds enough to surprise, while still maintaining a steady through line.While Models of Duration is technically a solo release, you will notice that Randall Dunn (Sunn O))), Master Musicians of Bukkake, Eyvind Kang, Oren Ambarchi, Earth, Anna Von Hausswolff, Six Organs of Admittance, Marissa Nadler, Boris, etc) is credited and also plays a major role on the record. The overall arc of the album is in large part due to Dunn’s deft recording and mixing. “Hoskin” should win an award for most intense clarinet recording ever made. Every time I listen the walls of my house shake and I couldn’t be happier. Rather than imposing his sound onto the album, Dunn helps bring out the aural magic in McCowen’s playing and compositions, a true collaborator in every sense.Models of Duration also marks McCowen’s first vinyl release, a co-release between Dinzu Artefacts and Astral Spirits. The physical & aural space that this record takes up while listening is truly stunning, an acoustic phenomena all on its own. While not a particularly easy listen, the album is also not entirely harsh either, an enveloping world that I don’t want to leave when the record ends.