She was 92 and lived in Manhattan.
A graduate of Hunter College, she trained as a modern dancer and toured the United States performing Spanish and modern dance during the 1920's.
She also performed with her sister, Elizabeth, in the late 1920's at the Neighborhood Playhouse.
She lived in Shanghai from 1948 to 1951 and was the first American dancer to teach modern dance in Chinese theater and dance schools.
Ms. Delza also became an expert on Chinese theatrical dancing after studying action dance roles in the classical Chinese theater with Wang Fu-Ying and Cheng Chuan-Chien. She gave lectures and dance recitals on the material throughout the United States.
She founded the Delza School of Tai Chi Chuan at Carnegie Hall in 1954 and later taught at schools including the State University of New York at Purchase, the Actor's Studio and the University of Hawaii.
She also taught and lectured on tai chi in live appearances and on television, writing the first book in English on the subject.
Her writings on esthetics, dance and theater arts and exercise and health have been published in China, in Europe and in American journals that include Dance Observer, the Theater Drama Review and the Journal of Aesthetics and Art Criticism.
Ms. Delza also published a record album on teaching tai chi and wrote four books on tai chi and modern dance, including "The Tai Chi Chuan Experience," published this year by the State University of New York Press.
Ms. Delza's husband, A. Cook Glassgold, an official of the Joint Distribution Committee in Shanghai and the United Nations Relief and Rehabilitation Agency, died in 1985.
She is survived by her sister, of Manhattan.