Max Weber’s music writings (including his unfinished ‘Music Study’) have always mesmerized readers but their importance for analysing music as a cultural domain has only started to be acknowledged. This paper focuses on Weber’s approach to the inner ‘developmental momentum’ of the music domain through his study of the particular tension that pervaded Western harmonic music. By showing how composers, performers, instrument manufacturers, art recipients and the instruments themselves had to grapple with such tension, Weber was able to give an account of the inward connection to an art sphere and its structuring effects, whilst also bringing social, economic and technological factors to bear. In the current debate on the desirable ways for a renewed sociology of culture to develop, Weber’s music writings present us with a path at once precarious and bold, an account of inner connections and outer relations, which, against Weber himself, also provides bases for aesthetic judgement.