Octave-reducing a fraction r means to make it fit into the range from 1 (the unisone) to (excluding) 2 (the octave):
1 <= r < 2
If r does not satisfy this inequality, it has to be
- multiplied by 2 while less than 1 or
- divided by 2 while greater than or equal to 2
Examples
- 3/4 is less than 1, so multiply by 2 to get 3/2
- 7/2 is greater than 2, so divide by 2 to get 7/4
- 4/2 is greater than 2, so divide by 2 to get 2, which is equal to 2, so divide by 2 to get 1