Everyone loves to hear music of some kind. All music is produced in frequencies .
Some musical instruments produce frequencies higher than the human ear can hear.
The range of frequencies that human hearing can discern is split into subranges, called octaves . An octave is defined as a frequency range such that the ending frequency is twice the beginning frequency. Octaves are defined in this way due to the logarithmic characteristics of human hearing. Piano keyboards are tuned based on a certain note, middle C , as shown in the figure below. Middle C has a frequency of 240 Hz.