This fifteen-minute piece takes its title, “Heart of Onyx,” from the Onix Ensemble of Mexico, which
commissioned it, but the music refers also to the durability of the stone, which, despite being so hard, lends
itself to being carved into many shapes; in Mexico it is often turned into wind chimes producing wonderful
sounds. The onyx is a stone at once strong and mutable.
Its character is rendered in this work in the contrast of harsh sounds with ideas that are more melodic or
more subtle. The trajectory of the piece unfolds in this direction and evolves through different sections in
which one idea may prevail and develop or be transformed. In this way, small ideas develop into large
sections, an example being the glissando of the strings. Also, ideas may be transformed, as happens when
the fluttertonging of the winds is developed into the staccatissimo or fortissimo clusters of the strings, which
are almost noise but become softer by changing the bow pressure as the glissando section opens. But
mostly, it is the opposition between ideas that creates the drama of the piece. (H. P.)