Density 21.5

Density 21.5 [1936-1946]

Density 21.5 is one of the twentieth century’s groundbreaking masterpieces for unaccompanied flute. The piece was written for the French flutist George Barrère’s new platinum instrument – the density of platinum is almost 21.5, thus the title. Unusually for this composer it does not require electronics. According to the composer, the work is based on two melodic ideas – one modal, one atonal – and the rest of the work explores these two themes. The technical innovations of Density 21.5 were the introduction of key-clicks, the extended use of the extreme upper register demonstrating the possibilities of the new platinum instrument and the re-definition of the flute as an instrument capable of a powerful musical intensity. That’s a lot of action for just under four minutes.