If you have a musical instrument, say a piano, set up so that the notes correspond to a Just scale based on \(\text{F}\) (the key of \(\text{F}\)) for example, changing to a key of \(\text{B}\) isn't ...If you have a musical instrument, say a piano, set up so that the notes correspond to a Just scale based on \(\text{F}\) (the key of \(\text{F}\)) for example, changing to a key of \(\text{B}\) isn't possible unless you add extra strings to the piano because there are new frequencies in the key of \(\text{B}\). Notes an octave above should be twice the frequency of the note in the lower octave but using the formula to generate the note doesn't give a frequency twice that of the lower octave.
