But it is actually called a perfect octave as well.

A full octave, a perfect octave, those are just technical terms.

However, it is enharmonically equivalent to the perfect octave.

Since they are the inverse of each other, by definition A4 and d5 always add up to exactly one perfect octave:

Again, I went home determined to perfect Octave harmonics.

In Semester 3 compound intervals from perfect octave to perfect 15th inclusive are used.

In equal temperament, this is equal to exactly one perfect octave:

Intervals: In Semester 1 all chromatic intervals up to and including the perfect octave are used.

It's actually called a perfect octave but they never worry about the perfect when you're talking about an octave.

The interval between C and C is a perfect 8th (perfect octave)

Notice that a justly tuned fifth is the most consonant interval after the perfect unison and the perfect octave.

It is because Musician Wrens preferentially produce successive perfect octaves, fifths, and fourths that their songs sound musical to human listeners.

Backed by perfect octave dyads, Stefani sings a verse about her excitement for her future, and the two personalities merge into one during the coda.

It can be thought of as the difference between four perfect octaves and seven just fifths, and functions as a chromatic semitone in a Pythagorean tuning.

In modern Western tonal music theory an augmented octave is the sum of a perfect octave and an augmented unison or chromatic semitone.

Modern western ears easily tolerate fast beating in non-just intervals (seconds and sevenths, thirds and sixths), but not in perfect octaves or fifths.

Three commonly cited examples of melodies featuring the perfect octave as their opening interval are "Singin' in the Rain", "Somewhere Over the Rainbow", and "Stranger on the Shore".

When the intervals surpass the perfect Octave (12 semitones), these intervals are called compound intervals, which include particularly the 9th, 11th, and 13th Intervals-widely used in jazz and blues Music.

Equal temperament, today the most common tuning system used in the West, accomplished this by flattening each fifth by a twelfth of a Pythagorean comma (approximately 2 cents), thus producing perfect octaves.

Of course, just intonation's perfect octaves, perfect fifths, and perfect fourths are well approximated in equal temperament tuning, and perfect fifths and octaves are highly consonant intervals.

Without adjusting the slide, the 1st to 2nd harmonic is a perfect octave, 2nd to 3rd harmonic is a 5th slightly wider than equal temperament and 4th to 5th harmonic is a major 3rd slightly narrower than in equal temperament.