Mary McCarron Maguire had a brief career as a popular composer in Sydney at the turn of the twentieth century. Her most famous composition was the Katoomba Waltz, written in honour of Sir Frederick Darley and Lady Darley. Sir Frederick Darley was Chief Justice and sometime Lieutenant Governor of NSW and owned a retreat in the Blue Mountains, Lilianfels.
Very few details are known about Maguire's life, other than that she was one of two daughters of a Woollahra family. They lived at Lansdown in Edgecliff Road, and were frequent guests at Government House and Admiralty House garden parties, and at Lord Mayoral receptions. Her sister Blanche was a semi-professional actress in the 1890s.
The Katoomba Waltz was premiered at Government House in the early 1890s, and was performed at the Tivoli Theatre in August 1895. Maguire wrote at least two other waltzes, the Antonina, and the Commonwealth, which celebrated Australia's Federation. No further works appear to have been published.
Maguire's name was the subject of a satirical poem in the Bulletin in November 1900, which suggests her possible notoriety in Sydney at least. She went to Europe in 1909, and was invited to the first annual meeting of the Teacher's Association of the British Empire, held at Caxton Hall, Westminster in 1913.