Abstract
Although non-octave music is not a well-known subject among composers or musicologists, “the avoidance of
octave doubling” was deemed especially important by the Modernist composer Arnold Schoenberg. This article
introduces composers and performers to two non-octave tunings invented by a German engineer named Heinz
Bohlen plus two octave-based tunings that can be used to approximate Bohlen’s tunings. The principal aim is to
encourage further practical experiments, not to indulge in phenomenological speculation. Relevant texts by William
Brouncker, Walter O’Connell and Kees van Prooijen are briefly discussed.
