Assertion: piano keyboard's octave | /r/HasProperty | excellent
Facets:
value: for verification
type: PURPOSE
Source sentences:
text: For the thirds in the temperament octave, it is difficult to tune so many beats per second, but after setting the temperament and duplicating it one octave below, all of these beat frequencies are present at half the indicated rate in this lower octave, which are excellent for verification that the temperament is correct.