Marshall was born in Toronto, and began her vocal studies there at an early age, first with Weldon Kilburn, and then with Emmy Heim. She first came to public notice in 1949, when she sang in Bach's St Matthew Passion with the Toronto Symphony Orchestra, conducted by Sir Ernest MacMillan. In 1952 she went to New York, where she won the Naumburg Award. This led to a concert in the Town Hall, as a result of which she was engaged by Toscanini for his 1953 NBC broadcast of Beethoven's Missa Solemnis, and for the subsequent recording of the work. Although the Italian maestro's interpretation of Beethoven's masterpiece was not to everybody's taste, this recording of the Missa Solemnis was an enormous success, and established Lois Marshall as a well-known figure in the musical world.
After a long tour of the United States, in 1956 Marshall came to England, making her London debut in a concert with the Royal Philharmonic conducted by Thomas Beecham. She also made a complete recording of Mozart's Die Entfuhring auf dem Serail with Beecham, in which she sang Konstanze. This should have been an ideal role for the soprano, who had all the power and the flexibility of voice required for Konstanze's music, in particular the aria "Martern aller Arten", but her performance, though very well sung, is curiously undramatic. On leaving England, Marshall gave concerts in Amsterdam, Brussels and Hamburg. In 1957 she sang at the Edinburgh Festival, and took part in a performance of Handel's Messiah in Dublin.
Marshall's operatic performances included the Queen of Night in Die Zauberflote, Donna Anna in Don Giovanni and the title role of Massenet's Therese in Toronto; Mimi in La Boheme and Tosca in Boston; and Ellen Orford in a CBC Television production of Britten's Peter Grimes. She gave popular duet recitals with Maureen Forrester, the Canadian contralto, and towards the end of her singing career she herself took on mezzo and contralto parts. From 1976 she taught voice in the Faculty of Music at the University of Toronto.
Lois Catherine Marshall, singer: born Toronto 29 January 1924; died Toronto 20 February 1997.