Musicology has recently re-evaluated the nature, form and purpose of musical biography, reflecting a broader ‘biographical turn’ in the humanities. This article takes up recent challenges to move beyond the traditional model of the ‘life and works’ of ‘great’ composers and joins the search for new paradigms of musical biography. The lives of the Australian microtonal composer Elsie Hamilton (1880–1965) and the British music archaeologist Kathleen Schlesinger (1862–1953), and their collaboration, which spanned three decades, are offered as a case study that demonstrates the importance of international and transnational networks for comparative musicology and modern music, and reveals the role of women as critical agents of scholarship and cultural transmission. It also lays bare the considerable influence exerted by the fin de siècle occult revival upon the search for new modalities of musical expression. It is an example of how a biographical approach allows an expansive examination of a mentalité and can bring together a range of discourses to reveal unrecognized connections and relationships.