(if
you are a string mechanic, that is...)
Here shown much exaggerated, a string swings freely either side of its octave node:~ hence the importance of this design (rotor shaft flaring).
Vibration in one plane only is very rare for music strings; the swing pattern is complex, as is the propagation of internal longitudinal shock waves...
These
shock waves can be considered as 'echoes' and in this arrangement,
will always be symmetrical either side of the octave node.
