http://www.youtube.com/watch?v=J4vVR0UQ0tQ An octave is an interval. The interval of an octave is the distance from one pitch to the same pitch 12 half steps away.
When you are reading octaves on sheet music they always fall with one note of the octave on a space and the other note of the octave on a line in the staff.
Throughout the range of the grand staff each octave has its own number assigned to it. An easy way to remember which number belongs to which octave is to memorize "Middle C = C4".
Octave numbers are assigned with each number spanning from C up to the next B. The next number appears at the next C.
Also, to calculate the frequency of an octave from any given beginning frecuency you will need to either:
- Multiply the original frequency by 2 for the octave above.
- Divide the original frequency by 2 for octave below.
To help you remember the information from this lesson click here to download a free poster with the octave numbers for the grand staff in the range of the piano keyboard.