The Language of Ballet : A Dictionary  by Thalia Mara 
 
This essential little book belongs in every dancer’s bag, especially those of students. It was a French ballet master who first codified ballet technique, and, therefore, French is the language of ballet. This dictionary lists every (French) word used for a movement, a step, or a concept in ballet with a complete and concise definition, and in many cases, an illustration. Also included are brief biographies of famous dancers and dance companies.