Density 21.5" – Inscribed Score "en evocation d'un staccato de timbales

New York : American Music Center, 1946. Used; Like New/Used; Like New. The French-American composer's only work for flute alone in its revised version. Quarto. 12 x 9.5 inches (30.5 x 24.3 cm). Unpaginated bifolium (2 pages of music). Inscribed by the composer to the title Peter Smith, then an engineering student working at the Columbia-Princeton Electronic Music Center, who had assisted Varèse with some of his early pioneering efforts in electronic music, and recalling their efforts together to achieve a computer-generated timables approximation: "à Peter Smith – en evocation d'un staccato de timbales /  Varèse." Browned, with slight loss to outer edge of first leaf, a few small nicks and tears to edges, and small red stain to title, head left; otherwise in fine condition.
In an email to Schubertiade Music & Arts, Peter Smith recalls that "in the course of that work, I assisted several well-known composers in how to use the electronic equipment in order to achieve their musical desires.  Edgard Varèse was one of those composers. Varèse and I spent several afternoons in the electronic music center where he would describe what he wanted to hear from the equipment and what he could achieve with the various recording techniques. I would teach how to properly splice the tape so that he could piece together the sounds that were in his mind for a particular composition.  We worked like this together for perhaps a period of 6 months." 

An interesting association copy from the pathbreaking composer who saw potential in using electronic mediums for sound production, and his use of new instruments and electronic resources led to his being known as the "Father of Electronic Music" while Henry Miller described him as "The stratospheric Colossus of Sound".
The piece for solo flute was composed in 1936 (revised in 1946) at the request of Georges Barrère for the premiere of his platinum flute, the density of platinum being close to 21.5 grams per cubic centimetre.  "According to the composer, Density 21.5 is based on two melodic ideas—one modal, one atonal—and all of the subsequent material is generated from these two themes. Despite the inherent limitations of writing for an unaccompanied melodic instrument, Varèse expertly explores new areas of space and time, utilizing registral contrasts to effect polyphonic continuity." (Sean Hickey, AllMusic)