Gives the frequency of a piano note. Or gives the note closest to a frequency.
Performs the calculation for each note or uses a pre-calculated frequency table.
For German notation (A,B,C,...) or solfege notation (do,re,mi,...).
It uses Free Pascal compiler: https://www.freepascal.org/
and MSEgui graphic widgetset: https://github.com/mse-org/mseide-msegui/
