Already in 1988, Keller put the following headline to an article: "Harmony is pacing out
borders." Do not stay frightened in the center, but make full use of what your time and location
allow you to! This still remains the task even under changed conditions. Still, the prospects and borders
for European musicians are not the same as those of musicians from other continents. Concerning the
music of the quartet, the European side shows especially in its references to the New Music from
Schönberg to Vinko Globokar. Thus, it is not the harmony of traditional jazz but its rhythms that are
being used, with the greatest interest lying in its african roots.
With his specially prepared piano, Hermann Keller has createda kind of fingerboard drums allowing the
creation of a diversity of sounds but most notably polyrhythmic structures. The engagement of different
rhythms during improvisation is characteristic of the whole group, not only involving a prepared trumpet
(with the well-known mutes) but also occasional preparations of violin and clarinet. Needless to say, a
"normal" piano is also (sometimes exclusively) being played in every concert, from simple triads to wild
clusters. Since all of the three colleagues of Hermann Keller play in other formations very different experiences
contribute to the music. To some extent, the improvisation is being controlled by models, sometimes by
composed music, on the other hand there is space for reacting to each other in a completely free manner.