From IBM’s blog (who knew IBM had a blog?),
[Charles] Ditchendorf remembers the dance typeball announcement because it was so unique. The typeball had special Labanotation symbols, developed in the 1920s by Hungarian dancer/choreographer Rudolf Laban to analyze and record movement and dance. The type-ball was issued with a grid “so that you could figure out how to put the movements together,” he said.
A symbol’s location showed which part of the body—arm, leg, torso—was to be used. The symbol’s shape indicated direction. The symbol’s shading showed the level of an arm or leg. And its length controlled the time value of a movement.
. . .
The typing element had 88 different symbols, which could be arranged to form a complete vocabulary for recording movement of any kind, from ballet and modern to ethnic, even folk. And the range of motions extends well beyond dance: Labanotation can also be used to record movements in areas like sports, behavioral sciences, physical therapy, and even industrial operations.
Ditchendorf says he doesn’t recall selling a single one of these, but some of them were definitely produced. For example, an index of papers compiled by the International Council of Kinetography Laban notes a 17 page guide drafted by one Yvette Algna titled, “The Speedy Production of Labanotation Scores with the IBM Typewriter Ball.”
Archive.Org is currently hosting a 1974 Manual for Use with the Labanotation – IBM Selectric Typewriter Element (I made an OCRed PDF version of the manual.