Negative harmony is a kind of harmony used in music. It's a way of writing chords that sound a little different and more interesting than normal chords. In negative harmony, chords are written using notes that are lower than the root of the chord. So, if you’re playing a C chord, you’d play notes like B, A, G, and F instead of notes like C, E, G, and B. This type of harmony creates interesting types of sounds that can add a unique feeling to music.