The aim of this thesis is to examine musico-dramatic development and motivic organisation in Fritz Bennicke Hart's seventh opera, "The Fantasticks" op. 35. It examines and comments on Hart's approach to the correlation between musical procedures, and dramatic and textural elements. It argues that Hart created and manipulated motifs that are effective and appropriate to the accompaniment and illustration of dramatic events, character elucidation, interpretation of emotional response, and generation of form. This thesis accompanies critical editions of the full score, piano/vocal score, and orchestra parts, and included a critical commentary. It also accompanies a premiere concert performance of the opera with full orchestra.