When one musical note has twice the frequency of another note the notes areapart?

When one musical note has twice the frequency of another note, the notes are an octave apart. In the context of music, this means that the higher note sounds like a more intense version of the lower note, and they share a strong harmonic relationship. For example, if the lower note is A at 440 Hz, the note an octave above it would be A at 880 Hz. This relationship is fundamental to musical scales and harmony.