During a long career, Baillie sang in complete recordings of Messiah, Elijah, Beethoven's Missa solemnis and Ninth Symphony. In the 1940s she formed a friendship with the contralto Kathleen Ferrier, with whom she appeared frequently in concert and made several recordings of duets. She took part in 19 annual Three Choirs Festivals from 1929. She made her American debut in 1933 and between then and her retirement from the concert platform in the mid 1950s she sang in the US, New Zealand, the Far East and Africa as well as in Europe.