Stephen Hartke

PERCOLATIVE PROCESSES (2005) for Percussion Ensemble Commissioned by the Natural History Museum of Los Angeles County Duration: 5 Minutes Percolative Processes was commissioned by the Los Angeles County Natural History Museum as part of their 2006 Sonic Scenery project, in which ten local composers and musical groups were asked to write site-specific pieces for Museum visitors to listen to over head-sets while touring the galleries of the permanent collections.  I selected the Hall of Minerals and Gems, a long-time favorite both of mine and my son, Sandy, and created a work for large percussion ensemble, that was then recorded in layers, making it possible for five players to do the work of thirteen. The piece is a reflection on the process of mineral formation, starting with inchoate sounds in cymbals and marimba, rippling murmurs, metallic sounds modulated by dipping instruments in water, then moves to harder-edged mallet percussion, both struck and bowed, and culminates in an angular chorale for vibraphone that crystallizes various motifs that have been heard along the way.  At the very end, as the last chord dies away, we hear a small metal hammer chipping at a piece of stone.

Recording: University of Houston Percussion Ensemble, Blake Wilkins, conductor Albany Records TROY 1333

Lynn Vartan et al., Donald Crockett, conductor NHM CD 001 (out of print)