Activism

MacArthur was active in social causes, including bringing concerts to prisons^[4] and to settlement houses. She was president of the Women's Auxiliary of the University Settlement Society of New York. During World War I, MacArthur was founder and president of Le Cercle Rochambeau, a women's war relief organization, and president of the National Association for Mothers of Defenders of Democracy.^[5] She had an apartment on the Champs-Élysées in Paris,^[6] and may have been involved in the Allied secret service during the war.^[3] She wrote "Short Talk on Suffrage" (1915), noting that "We suffer from inertia and from the dread of big changes which seem in the nature of upheavals. We will often go on reading in a failing light rather than move and turn on a full light."^[7]

She was active in the National Council of Women's Department of Community Music, and founder and president of New York's Thursday Musical Club.^[8] She was not a professional pianist, but played socially, on the radio,^[9] and at benefit concerts with other musicians.^[10]

The Apocalypse

As a librettist, MacArthur was known as co-writer (with Henri Pierre Roché) of The Apocalypse (1921), a dramatic oratorio.^[11] The Apocalypse was based on Biblical themes (with sections titled "Belshazzar's Feast", "Armageddon", "Babylon", and "The Millennium"), but also had clear references to the more recent trauma of World War I.^[12] The National Federation of Music Clubs held a contest, and awarded $5000 to the MacArthur/Roché libretto and the music by Paolo Gallico.^[8][13] The Apocalypse was first performed at the Federation's biennial meeting in Davenport, Iowa, in 1921; the following year, was performed by the Oratorio Society of New York, at Carnegie Hall.^[14]