Is a synonym for distance octave?

"Octave" itself is a specific musical interval, so it doesn't really have a synonym in the sense of a word meaning the same thing.

However, depending on the context, you might use words like:

* Interval: A more general term for the distance between two notes.

* Spacing: Describes the physical distance between notes on a keyboard or musical staff.

* Range: Refers to the overall extent of notes that can be played or sung.

For example:

* "The distance between C and the next C is an octave."

* "The interval of an octave is often used in harmony."

* "The piano has a wide range, encompassing many octaves."

Ultimately, the best word to use depends on the specific meaning you want to convey.