This paper tells the story of Sister Mary Theresa Brentano, O.S.B's (1902-1987) innovative use of magnetic audiotapes to provide instruction for students in grades K-12. From 1952 to approximately 1968, Brentano implemented, refined, and tested her tape teaching methods with special emphasis on individualizing instruction in the elementary school. Brentano's innovative tape teaching ideas are not mentioned in Saettler's "The Evolution of American Educational Technology" (1990), DeVaney's "Voices of the Founders: Early Discourses in Educational Technology" (1996), or Butler's "Women in Audiovisual Education, 1920-1957: A Discourse Analysis" (1995). This paper provides an interpretive biographical look at Brentano's tape teaching innovation. It discusses her rationale for and implementation of tape teaching and shares some of the successes and struggles of tape teaching. The paper concludes by discussing two ways this research into Brentano's individualized tape teaching innovation benefits the field of educational technology. (Contains 29 references.) (AEF)