Quintenzirkel
(C) 2022 Alexander Groß
The present program is subject to the GNU GPL version 3, which is included in
the file COPYING the source code.
I use the international notation in the program, so german H = B,
German B = A#, also I don't use flats, but use the respective sharp
variant, i.e. Bb = A#.
The application is written in Python and uses Kivy (https://kivy.org)
as GUI library, but no other than the standard Python libs.