Density 21.5

Density 21.5 is a composition for flute solo by Edgar Varèse. The 1936 resulting piece is regarded as trend-setting composition of the 20th century solo inside the relatively narrow repertoire for flute.

A native of Paris composer Edgar Varèse, since 1927, U.S. citizen, wrote Density 21.5 on behalf of the originating also from France flutist Georges Barrere in January 1936 (1946 the plant was again revised). Barrere had been gifted by the influential patron Elizabeth Sprague Coolidge with a flute made ​​of platinum, a hitherto unusual material for an instrument that - unless of wood - was mostly made of silver or gold. The selected title by Varèse composed of the inauguration of Barreres platinum flute work refers to this special, very heavy precious metal whose density is (English " Density" ) 21.5.

The plant with a playing time of about 4 minutes includes 61 bars. A composition eröffnendes motif of descending smaller, followed by an ascending major second is the nucleus of a development that the entire tonal range of the flute (from c ' to d '''') traverses. The use of different registers of the flute with their specific expression in addition to thematic development and expansion of the intervals constructive part of the instructions provided with differentiated dynamic composition. In the first half, the music moves in low and intermediate altitudes of the instrument, while in the second half mainly the high are used to the highest register.

Probably for the first time in the history of the flute using Varèse explicitly clatter as an additional means of expression. In a three-bar passage mark crosses over the notes sound, in which the doors are to be beaten vigorously to produce in addition to blown sound a percussive effect.