Young will demonstrate the pitch structures from which Cross-Current is constructed, of which there are two types. The first are groups of pitches whose ratios share a prime number, the second are ratios which, when added to one another, form a unison with a different ratio. For instance, two 9/7’s (81/49) form a unison with 5/3, both ratios falling within ten cents of a pitch in the Bohlen-Pierce scale.
The changing directions of water flow shape the clarinet part, and the movements of river-bottom rocks across the screen shape the percussion parts, the pitch structures shifting with the changing directions of movement in the video. James Tenney’s concept of harmonic space is taken rather literally here, as if the video itself were illustrating the vectors of a diagram of harmonic space. Young will also discuss the role of Reitzenstein’s video in the context of Earle Brown’s composition December 1952, for which Brown originally intended to build a horizontal motorized mobile, to which the musicians would respond.