I'd like to know in what period/year chords were invented and by whom.
Did musicians like Bach, Mozart, and Beethoven think in chords to harmonize their melodies or did chords only emerge in the 1900s?
note: this is a secondary question to my question Why aren't chords written in classical sheet music? one of the commenters said that chords weren't invented during that time, which was very surprising for me to hear. so I want to know when they were invented.