How many times in the history of jazz, have attempts to define jazz been made, rejected by musicians themselves, who proceed to make music without definition, without seeming limitations, or borders within their sonorous conference. How many ways can musical sound be defined. That is the place where we have to start. Not necessarily with the scientific Hertzian viewpoint, but within context of the temporal, perhaps with the in-the-back-of-the-mind historical outlook, and most importantly, within the present tense circumstance.
With this quartet, it is made clear that improvisational music is a process of many levels of timbre, intensity, emotion, and wrought-ing up. McPhee (on the trumpet and pocket cornet as well as tenor sax) and Brötzmann (on alto and tenor) are often distinguishable due to the attack of their instruments, especially if you know their playing. The many unisons make your heart leap. The continuity of ostinatos is precious and indelible and most often provides a component of rhythmic repetition. Sometimes the delicacy of the horns can take you to a place to which you want to return frequently.
When Kessler on bass and Zerang on drums come in, they either aurally mollify the hard edge of the horns but also open the gates so that the abstractions from the horns can fly. The bass and drums act mostly as percussive elements rather than as rhythm keepers which drive the horns to unrelenting territory. The horns seem to come to many unified resolutions which is a gratifying conclusion for some of the pieces even though what seem to be the resolutions are not heavy but just float there in the aural air.
Several of the tracks are tributes to other people, musicians, who have passed on. The mix of authorship of composition and performance is surprising and quite wonderful. The poetry is gripping. You have to find it....because it only can be described in the music that it is.
We have to graduate beyond the science of analysis to appreciate the music we hear no matter how difficult it is to listen to in its moments of travel. Not all travel, not all journeys are smooth and easy. And some journeys simply end.