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Frequency
number of waveform cycles per second
what frequency A3 is
440 Hz
what frequency A4 is
880 Hz
how you calculate an octave higher in frequency
double the original Frequency
how you calculate an octave lower in frequency
half the original frequency
how to calculate a perfect 5th higher
n x 1.5
how to calculate a perfect 4th lower
n x 0.75