A perfect octave
Perfect
Open interval does not include its end points while closed interval includes
An interval is the spacing of time. For example: I ran for an interval of 10 minutes then walked for an interval of 30 minutes. Or each car has an interval of 0.5 seconds.
There is no interval in a single number.
2:1
He discovered the ratio of a perfect octave is 2:1.
perfect fourth !
A perfect octave
He discovered the ratio interval of a perfect octave is 2:1.
Perfect
Perfect fourth
Perfect
Perfect
Perfect octave.
perfect fourth
An octave is defined as two notes, one of which is twice the frequency (vibrations per second) as the other; also two notes with an interval between them of 8 diatonic degrees.