[2] After studying music theory with Mary Mason at the New England Conservatory in Boston, Parker attended Smith College in Northampton, Massachusetts, graduating in 1947 with a double major in organ and composition.

She then spent a summer at Tanglewood, studying with the conductor Robert Shaw, with whom she went on to have a long and prolific association, and Julius Herford, before beginning a graduate program in choral conducting at the Juilliard School in New York City.

[1][2][8] In Hawley she founded the professional choir Melodious Accord in 1985, with which she released 14 albums and established a fellowship program to enable mid-career musicians to study with her.

Produced by HFP in association with Melodious Accord, Inc., it focuses on Parker's formative years and her collaboration on texts by Martin Luther King Jr., Archibald MacLeish, Eudora Welty and Emily Dickinson.

[1][4][13] Following his death from a heart attack, a choir made up of 400 of his acquaintances sang Brahms's A German Requiem at his memorial service at the Cathedral of St. John the Divine in New York.