Collecting the material
A central idea in post tonal theory is the importance of the intervallic relationship present a group of pitches, or a ”set”, each one having its own particular ”flavour” or ”colour”. As long as this intervallic relationship stays intact the pitches can be changed, the order can be rearranged, used in different transpositions and permutations, played backwards, ascending or descending but the ”flavour” of the set is still present. The intervallic relationship itself creates a vague type of harmonic coherence.
When I started working on the music for Moineaux, I started out with only three pitches. In Moineaux II the trichord D, E, G (or [0,2,5] in ”normal form”) is abundantly present. The focus is put on the intervallic pattern of one whole step and then one minor third. By experimenting with these relationships in different ways I arrived at the series of notes shown below.
Example 1 shows the above mentioned trichord written from D. Next to it is a series of pitches formed as what I call a ”trichord chain”. This scale-like pattern formed one of the composed elements used in Moineaux II. The construction is based on the idea of common-tone transposition, the last note in the trichord (G) becomes the first in a new trichord that has the same intervallic pattern, and so the pattern repeats.
What I liked about this particular construction is that it starts out as the common D-minor pentatonic scale and, deceptively, familiar to the ear. At the same time it keeps transposing for every new set of three notes and creates a modulating effect that through the force of its inner logic goes astray from the expected traditional key center. This ambivalence regarding the key center has another dimension to it as it is also connected to register. Depending on where you are in the scale you will have different central tones, any of the pivotal notes D, G, C or F could be of equal importance. In a way this creates a sensation similar to a ”Möbius strip” with no beginning or end. The ambivalence is originating in the tonal material itself and I have found this helpful when combining written and improvised parts. It allows for the improviser not to feel like one is stuck in one key, that can sometimes get tiresome. At the same time this organized element helps maintaining a similar colour throughout the piece that, I believe, makes it more coherent.
In Moineaux II the "trichord-chain" serves as both a written line that appears on several occasions in the piece and also as a ”playing scale” - that is a source from where the players can build their sounds when improvising. To move between the two, one of the players can decide when to cue the written part by playing the written phrase. This also sets the tempo as the improvisation otherwise stays ”out of time”.
The material in itself provides a colour where the ambiguity of tonal center and absence of any harmonic progression invites the music to stay immobile. Movement and form is created by other means. The improvised parts start out very sparse and get progressively more dense and intense. The introduction of a strict tempo contrasts the original out of time feel and provides a new section in the music.
This music was written and performed during the spring term 2022 together with the taiwanese pipa player Fan Qi Wu and the trumpeter / hornist Adrian Barstad Andressen from Norway. The two pieces are the result of experimenting with composing music where all harmonic materials stem from a a single trichord. In the text below I will go into more detail on how the compositions were constructed.
This series of chords is also used to create melodic material as the trumpet plays the top note in each chord. The line of the top note of each chord forms its own scale with that resembles other, more familiar, scales like the ”be-bop scale”often associated to jazz or the half step/whole step symmetric scale. Treating the original trichord in this way opens many possibilities harmonically and provides a way for me to expand on sounds I am already familiar improvising with in a way that also feels coherent with the piece as a whole.
Working with the compositions has also been a reflection on different ways of organizing harmony when composing for improvisers. I would now like to discuss how this harmonic content is treated in the improvised parts. In the two pieces presented the improvisation is organized in different ways. In Moineaux I there is a written layer that is played by the trumpet and the guitar contrasted by an improvised layer played by the pipa. All players read the score to be able to follow what is happening in the other layer. Both layers exist independently from each other metrically but follow the same dynamic curve culminating in a ff. The improvised part is given a few harmonic guidelines notated as scales as a help to more easily adapt to the chord changes. These should only be considered as suggestions of melodic material and are not to be played as scales up and down.
In Moineaux II the improvisation is played collectively in the trio within a given frame (the ”playing scale” and no tempo in A, strictly in tempo in B). The improvisation is divided into sections by the composed element. There are written instructions regarding the density of the improvised parts. As described earlier the playing scale creates some tonal ambiguity by the way it is constructed. One interesting aspect of this is the connection to register, the pitch Bb is only found in the high register where as G and D can be played both in a low or middle register. The harmonic framework of this piece is in this sens quite narrow, something which is compensated through a lot of freedom in spacing of the interplay.
To sum it up. For me, a way of answering the initial questions about tonal coherence and combining the improvised with the written starts with the material itself. Using tonal material that recall familiar sounds from the major/minor world but at the same time, through its inner logic, goes beyond the usual tonal boundaries, gives the improviser a bigger freedom to move both inside and outside of a tonality. It also provides some security for the improvisers who might not be very familiar with post tonal theory, simplifying the understanding of the harmonic framework. The use of tonal material derived from a common source both in written parts and as a framework for improvisation has provided me with a link between the two. The written elements in this otherwise improvised setting also provide anchor points for the listener and strengthens the identity of the piece by adding a formal element.
Expanding on the material
The piece called Moineaux I, is based on the same trichord as Moineax II, exploring other harmonic possibilities. The piece opens with presenting three adjacent pitches, D, Db and Eb, the D is played alone and Db, Eb together. Throughout the piece more and more pitches are added to form bigger and bigger chords. The construction of these chords is based on the trichord-chain discussed above played out as mirror harmony departing from D, Db & Eb respectively as shown in example 2 below.
One can see the shape of the chords being ”mirrored” from the D in the middle in the first bar. In the second bar the pattern is played ascending from Eb and descending from Db creating a second group of chords. When the chords from the example above are combined and ordered from smallest to biggest outer interval the result is the harmonic material used in Moineaux I (example 3).