Pauline Oliveros: Heart of Tones
For trombone solo with two or more oscillators, or for three or more trombones, or trombone and any two or more instruments that can increment or slide a half step above or below D4. Strings, winds, voices, etc. up to a small orchestra.
Tune to D4.
Trombone and oscillators or other instruments gently establish D4 as a drone with timbral and spatial shifts.
After the drone is established, slowly deviate individually from D4 in just perceptible differences—increments or glisses of one or more cents. The upper limit if D-flat and the lower limit C-sharp. Play inside these half steps using continually shifting timbres and return to D4 without exceeding the half-step limits.
Trombone shifts the direction of the bell to create spatial patterns as well. Other acoustic instruments analogously shift direction of sound.
Listen for partials, beats, and the subtle shifts in beat patterns. The beats will also be affected by the spatial and timbral patterns.
At least one instrument or oscillator is always sounding and continually moving spatially or changing timbre. The changes are slow—glacial.
Dynamics are free ad also continually changing. During envelopes of intensity, rapid trills, tonguing, or bowing patterns could occur.
Get to the heart of the matter! Define the space with sound. —Pauline Oliveros