Non-Chord tones are also known as Nonharmonic tones or Embellishing tones. They can best be described by how they are approached, how they are resolved, and the direction of resolution. A Non-Chord tone is simply any note that is not a member of the chord identified. A step is the distance of a major or minor 2nd in either direction. A leap is a skip of a 3rd or larger. To retain a note is to repeat it or hold the note in the same voice. For example, Passing Tones and Neighboring Tones are both approached by step and resolved by step, but they resolve in different directions. The PT continues up or down in the same direction, while the NT steps back in the opposite direction to the note it came from. The table below shows how the eight common NCTs are defined.
These two types of NCTs are held or repeated, so they are created by the voices moving around them. Suspensions are also indicated in the figured bass numbers. Common suspensions are the 9-8, 7-6, 4-3, and the 2-3 bass suspension. They always resolve down a step. Retardations are not numbered, and they always step up to their note of resolution.