Two notes form an octave how are there frequencies related?

Answer 1

Any note sounds similar to the note an octave above it- to understand this you have to know that each musical note can be represented by a frequency in Herz (Hz). This tells you how many times a string would vibrate per second if you were to tune the string to that note. For example, the A above middle C is standard at 440 Hz. A string vibrates back and forth 440 times per second to make this note. If you were to play an A an octave above the one you just played, you would have to make the string vibrate twice as fast. In other words, it would be vibrating at 880 Hz (440 x 2). And if you wanted to go an octave below A 440, you would divide the number in half to get 220 Hz. The ratio of the frequency of any note (including a C) to the frequency of a note an octave below it is 1:2.

If were able to freeze a string in mid-vibration and look at the actual physical positions of it as it vibrates twice as fast, you would see that the base note would be vibrating like the outline of an eye, which the note an octave above it would be vibrating like the shape of a sideways figure 8 with pointy ends. You can try it yourself with a long rubber band- pluck the note of the whole length of the rubber band. Now divide it in half with your finger. You will get a note one octave above it.

Hope I made things better instead of worse!

Answer 2

Two notes are said to be form an octave when the frequency of the higher note is twice the frequency of the lower note.