African Winds (1998), originally written for bass clarinet and percussion, was commissioned by Duo Contemporain (Enri Bok and Miquel Bernat). I made two versions: one for saxophone and percussion (2008) and the one in this album for two marimbas and vibraphone, composed in 2005. As in previous works, the quest in African Winds II targets the relation between harmony and timbre. From the opening bars, three figures, of one, two and three pulses, combine between the two players to create a non-linear, highly fragmented and apparently regular rhythmic fabric, but which is not actually like that thanks to a shifting articulation that proliferates in an uninterrupted continuum of semiquavers lasting until the work ends, and articulated as follows: (1+3) (1+2) (1+1), (2+3) (2+2) (2+1), (3+1) (3+2) (3+1).

One of the most notable characteristics of this sort of writing, which I have used many times, is the fragmentation of the spectrum into short segments: even at points sometimes situated in regions of harmonics which are consecutive (17, 18, 19, 20, 21, etc.), close (2, 3, 5, 7, 11, 17, etc.) or in others which are very distant (2, 17, 3, 18, 5, 19, 20, etc.). These brief figures are enlarged and transformed at a given point, shifting from 1, 2 and 3 pulses (semiquavers) to 4, 6, 9, 11, 13 or 17, the last of these always linear, ascending or descending, allowing me to create an intermediate combinatory formal play, inserting the ascending or descending gestures of the correlative harmonics 4, 6, 8, 9, 11, 13, 17, between large blocks of fragmented micro-structures: (1+3) (2+1) (1+1), (3+2) (3+1) etc.

This idea extends still to another area of the polyphony, as will be seen, where the elements are no longer treated as combining points and segments and the interpolation of ascending or descending lines of harmonics, but as macro-structures of blocks of a certain number of bars. This allows me to maintain the continuity and, at the same time, the sensation of compression and expansion of structures, combining components from different temporal orders, that is from different polyphonic levels. In harmonic terms, each of the notes (frequencies) constituting these figures forms part of a filtered harmonic spectrum, adjusted to semitones, that modulates constantly, sound spectrums where I eliminate the harmonics repeated in successive octaves so that just 12 frequencies remain active:

Fundamental, (f.2), f.3, (f.4), f.5, (f.6), f.7, (f.8), f.9, (f.10), f.11, (f.12), f.13, (f.14), f.15, (f.16), f.17, (f.18), f.19, (f.20), f.21, (f.22), (f.23), (f.24), f.25.

Twelve frequencies integrated and creating a system which is not modal, or tonal, or serial, but timbral-spectral. Thus the musical idea focuses on the sound representation of abstract physical-mathematical thinking, highlighting the physical-acoustical laws of sound. From the formal point of view, the work develops in the framework of an apparently free organic structure; only apparently, because the interest of the organicity lies in a control of the freedom and the balance of all the parameters involved in the composition. I achieve this by constantly listening and re-listening internally to the music already written, to discover and evaluate which of the paths possible at any time interests me to follow. Tinged with diverse colours, dynamics, registers, timbres and forms of attack, the figures referred to above provide the basis for very varied musical situations, giving rise to successions of colours crossing or coinciding in an asymmetrical continuity. This pictorial effect, which creates different depths within the regularity of a texture, enables us in music to obtain different planes and profundities whether in rhythm or in harmony and timbre. In the case of the rhythm, the result frequently evokes thirteenth and fourteenth century hocket techniques of the Ars Antiqua, from the School of Notre Dame, as well as African polyphonies, where a melody or a harmony is shared and fragmented among the various voices in a work. For me, clearly, timbre is the category which is shared and spatialised, the harmonics being those that jump from one player to another, from one voice to another. The outcome is a polyphonic unit at once fragmented yet compact where time, the main protagonist, evolves and binds different dimensions of its multiple essence. When the fabric supporting this structure disappears, we enter a poetic world of musical abstraction and of inexplicable sound images borne by the wind.

José Manuel López López