Double the frequency
The octave.
Same note, higher up
A singer sings a note, then sings the same note higher, one octave up. The second note has a frequency that is related to the first.
If the first note has a frequency of 200 Hz, what do you think the frequency of the note one octave higher is?
What this lesson covers
The idea
An octave is the interval between two notes where one has double the frequency of the other, measured between their fundamental frequencies.
Same note, higher up
A singer sings a note, then sings the same note higher, one octave up. The second note has a frequency that is related to the first.
If the first note has a frequency of 200 Hz, what do you think the frequency of the note one octave higher is?
- 400 Hz
- 300 Hz
- 201 Hz
Compare two notes
Choose the frequency of the lower note. The frequencies are only examples.
Twice as many
An octave is the interval between two notes where one has double the frequency of the other, for example 200 Hz and 400 Hz. It is measured between the fundamental frequencies of the notes.
An octave is the interval between two notes where one has double the frequency of the other. It is measured between their fundamental frequencies.
Notes
An octave is the interval between two notes where one has double the frequency of the other, measured between their fundamental frequencies.
Check yourself
A note has a fundamental frequency of 250 Hz (an example). What is the frequency of the note one octave higher, in Hz?
Answer: 500 Hz
One octave higher means double the frequency: 2 × 250 Hz = 500 Hz.
Two notes are one octave apart. The higher note has a frequency of 400 Hz. What is the frequency of the lower note, in Hz?
Answer: 200 Hz
The higher note has double the frequency, so the lower note is 400 Hz ÷ 2 = 200 Hz.
What is an octave?
Between which frequencies is an octave measured?
- The interval between two notes where one has double the frequency of the other — correct. Yes!
- The interval between two notes where one is twice as loud. An octave is about frequency: one note has double the frequency of the other.
- A note made of eight tones played together. An octave is the interval between two notes where one has double the frequency of the other.
- The overtones of the two notes. The octave is measured between the fundamental frequencies.
- The fundamental frequencies of the two notes — correct. Yes!
- The amplitudes of the two notes. An octave is about frequency, measured between the fundamental frequencies.