“MacBenesh” is a graphics editor designed to create single-dancer BMN scores. The application was originally developed in 1984 to run on the Apple Macintosh personal computer. See MacBenesh: A “Word Processor” for Choreologist.
MacBenesh development was suspended when Benesh International began creating the Benesh Notation Editor (BNE) for multi-dancer BMN scores. BNE runs on PC Windows software.
In 2017, in response to renewed interest in MacBenesh, Arthur Ryman created documentation outlining how to run MacBenesh under Mac OS X using SheepShaver. You can download the necessary files and instructions for free.
If you have success getting MacBenesh working, you may wish to download The MacBenesh Manual created by Ryman, R.S., R. Hughes Ryman and M.M. Marcovici: University of Waterloo, 1990 (orig. 1987). Needless to say the user manual is out-of-date, but hopefully it will help you understand how MacBenesh works.