This article looks at ways in which the notion of music as a language with a literature operated in English girls' secondary education in the inter-war years. It explores musical literacies and multi-modality in the music curriculum of two inter-war music teachers working in girls' schools: Margaret Donington and Annie Warburton. Both contributed to the professionalisation processes at work within secondary education for girls, within music teaching, and within women's position in musical performance and composition more generally. In tracing meanings of musical literacy and literacy practices around music in the work of the two women, the article looks first at the notion that music was a language in sound with a grammar into which the pupil was to be inducted. Second, it examines the introduction of the pupil to the technical vocabulary of European music through which this sound language was described. Third, it explores aspects that pertained to the "literature" of music. The article also traces the interrelation of aural, oral, visual, kinaesthetic and cognitive learning in the development of the "good ear", which was used to characterise the musically literate pupil and stood for the competences of the pupil related to what counted as musical literacy. The article looks, too, at ways in which multi-modality in the curriculum was systematically reduced in the development of a more limited mode of highly developed cognitive decoding based on the aural and the visual. It considers how the deployment of literacy practices related to the material history of the music classroom and to underlying aspects of progressive pedagogy with Spencerian roots. The development of musical literacy and literacy practices around music in girls' education is discussed in the context of an increasing stress on the "aesthetic attitude" in inter-war England that was seen to relate to a need to re-invigorate national culture and re-order domestic life, which were thought to have been "unsettled" as a result of war, and to developing discourses of psychology that pointed to the importance of the "inner" self. (Contains 75 footnotes.)