The one interval where the higher tone merges back into its own prime, which Steiner heard as the soul finding its self again, lifted a level.
The octave in Anthroposophy is the interval Rudolf Steiner treated as the soul meeting its own self on a higher rung. In his 1920 lectures on the inner nature of music, he noted that the eighth tone, unlike a third or a fifth, cannot be told apart from the prime that begot it; the two fuse. From that fusion comes a feeling he phrased as "I have found my 'I' anew."
In Steiner's Own Words
While the seventh is still felt in relation to the prime, an entirely different experience arises as soon as the octave appears. One cannot actually distinguish it any longer from the prime; it merges with the prime. In any case, the difference that exists for a fifth or a third is absent for an octave. Of course, we do have a feeling for the octave, but this is not yet the feeling that will be developed in time; in the future the feeling for the octave will be something completely different and will one day be able to deepen the musical experience tremendously. Every time the octave appears in a musical composition, man will have a feeling that I can only describe with the words, “I have found my ‘I’ anew; I am uplifted in my humanity by the feeling for the octave.”
What it Means Today
Steiner framed the octave as a feeling still ripening in humanity, and the place that feeling is now consciously worked is tone eurythmy, the movement art his collaborators built from the same 1920 musical insights. At the Eurythmeum Stuttgart, founded in 1923 by Else Klink in the city where Steiner gave these very lectures, eurythmists learned to render each interval as a distinct gesture. There the octave is not danced as a brand-new note but as the prime carried upward and reopened, the body crossing forward so that the gesture which began the scale returns enlarged. A practitioner trains the difference Steiner described: a third is held inward, close to the breast, because it draws the soul into itself; the octave is given forward and out, because it hands the self back to itself on a higher plane. That craft makes the abstract claim testable in the limbs. A singer can verify it too. Sound a low c, then its octave, and notice how the second tone does not introduce a stranger but answers the first, as though the same person had spoken twice. Steiner's reading of the octave, the prime recovered an eighth higher, gives a spiritual name to that plain musical fact: the interval where you meet yourself again.
Where to Read More