Question: What are the existing musical chords ?
Answers:
answer_text: Augmented eleventh chord Pearse, John (1977). The Guitarists Picture Chord Encyclopedia, p.31. . 
answer_text: Augmented major seventh chord
answer_text: Augmented seventh chord
answer_text: Augmented sixth chord
answer_text: Diminished major seventh chord
answer_text: Diminished seventh chord (leading-tone and secondary chord)
answer_text: Dominant
answer_text: Dominant ninth
answer_text: Dominant parallel
answer_text: Dominant seventh chord
answer_text: Dominant seventh flat five chord
answer_text: Dominant seventh sharp nine / Hendrix chord
answer_text: Dominant thirteenth chord
answer_text: Elektra chord
answer_text: Half-diminished seventh chord
answer_text: Harmonic seventh chord
answer_text: Lydian chord
answer_text: Major chord
answer_text: Major sixth chord
answer_text: Major sixth ninth chord ("6 add 9",  Nine six, Pearse (1977), p.35.  6/9)
answer_text: Major ninth chord
answer_text: Major thirteenth chord
answer_text: Minor major seventh chord
answer_text: Minor ninth chord
answer_text: Minor seventh chord
answer_text: Minor sixth chord
answer_text: Minor thirteenth chord
answer_text: Mu chord
answer_text: Ninth flat fifth chord 
answer_text: Power chord P5
answer_text: So What chord
answer_text: Subdominant parallel
answer_text: Subtonic
answer_text: Supertonic
answer_text: Thirteenth flat ninth chord 
answer_text: Thirteenth flat ninth flat fifth chord 
answer_text: Tonic counter parallel
answer_text: Viennese trichord