👉 Atis is a term used in the context of music theory, specifically in the study of scales and chord progressions. It refers to the "attribution" or "attribution of" a particular scale or chord, which is an extension of a given scale or chord. The term was introduced by German composer Johann Sebastian Bach and is often associated with the concept of "schiffrungslehre," which in turn is derived from the Latin word "schiff," meaning "to change."