A 65th chord, often referred to as a six-five chord, is a type of triadic harmony that includes a root, a third, and a fifth, with the fifth being the lowest note. This chord is typically used in music theory to create a sense of tension and resolution, often leading to a more stable chord. In classical music, the 65th chord is commonly found in figured bass notation, where the numbers indicate the intervals above the bass note. It is frequently used in chord progressions to enhance the emotional impact of a piece, providing a richer harmonic texture.