While some sources give Julia Smith's birth date as 1911, her birth certificate confirms a date of January 25, 1905 in Caldwell, Texas, to James Willis Smith and Julia Miller Smith of 1105 Mulberry Street in Denton, Texas. She took her first piano lesson from her mother, and later studied piano with Harold von Mickwitz of Dallas while she was a student at North Texas State Teachers' College. Smith graduated in 1930 with a degree in English and went to New York to study piano performance at the Juilliard School of Music. Her teacher, Carl Friedberg, encouraged her to pursue composition at the School. Smith became a composition fellow and spent five more years at Juilliard studying with Rubin Goldmark and Frederick Jacobi. In 1938, Smith married architect Oscar Vielehr. The following year, Smith's first opera, Cynthia Parker, received its premiere at her alma mater. The opera was based on the legendary Texas abduction and recapture of its title character. Cynthia Parker enjoyed a much-publicized premiere. Smith's next opera, The Stranger of Manzano, was also premiered at NTSTC (1945). She is best known for her six operas and biography of Aaron Copland (1955), and spent over fifty years as a composer, pianist, and advocate of American music. Smith's date of death is recorded as April 18 or April 27, 1989, with her grave stone displaying the latter date.