A Chime is a set of bells that can play music, but is smaller than a Carillon. To be useful, the chime should encompass a span of one octave (8 notes). In addition, semitones are often employed to enlarge the number of musical selections that can be played. The most-often added semitone is the minor-seventh. Additionally, many chimes include the sharp-fourth.

The musical libraries Chime Master provides for Chime-sized bell controllers are coded with three digit numbers, the first two being the number of and the third digit representing the number of additional semitones. It is assumed that one semitone will always be the minor-seventh and two will include both the minor-seventh and the sharp-fourth. Other custom libraries can be built if additional semitones exist in your chime.