This book is a new development of a project that began in the 1980s, when the subject of female composers—whose work had been neglected for centuries—was beginning to gain traction among music historians and performers. I had completed a doctoral dissertation about the source materials for the compositions of Gustav Mahler at Northwestern University, and in subsequent years, I learned for the first time that his wife, Alma Schindler-Mahler, was a composer in her own right, some of whose works were traceable in libraries. In my early work about Alma Mahler, I considered the relationship between her work and that of her husband, a methodology that involved historical context as well as musical style. It was not new in those days, since the relationship of the Mahlers was comparable to the situation of other female composers affected by association with male composers related to them by birth or marriage, e.g. Robert and Clara Schumann, Felix and Fanny Mendelssohn and possibly Wolfgang and Nannerl Mozart.