ChordCalculus is a tool for players of fretted instruments. ChordCalculus will allow the user to choose from a large number of pre-defined fretted instruments in a variety of tunings. Additionally, the user can define new instruments and/or tunings. Single or multiple capos can be added. The user then picks from one of four operating modes using the segmented selectors at the center top of the display: * (C)hord Calculator: Show all fingerings for chords for a given instrument/tuning, filters, capos, and fret span. * Chord (I)dentifer: For a given instrument/tuning and fingering, display all possible names for a chord * (S)cale Display: For an instrument/tuning, key and scale type, display the scale, and play a two-octave scale * (P)rogression Player: Derived from chord mode, display fingerings for a chord progression. Also plays chords in sequence. In all cases, the chords can be played as a chord or arpeggio and the scale played back. As of version 2.0, an instrument tuner is accessed by long touching the tuning button. See https://www.youtube.com/watch?v=Ty5eI_DiXhk&t=20s for all the features