The piano-vocal scores of musical theatre songs often contain simplistic and uninspired piano writing. Characteristically, the scores have right-hand figuration that doubles the voice line, restricting the singer from having the rhythmic and melodic freedom that is an essential component of the style. In addition, the piano-vocal scores have shallow bass lines and thin textures, making it difficult for the pianist to offer the support and expression that the music deserves. Editors may choose this writing style to make the score pianistically accessible for voice teachers accompanying their students, or to provide melodic assistance for less experienced singers. Conductor-vocal scores do exist and more closely resemble what an orchestra might play, but they are expensive, at times only available as rental scores, or highly inconvenient to locate. Therefore, I have designed twelve techniques to enhance piano-vocal scores, and will demonstrate those techniques through seven songs selected from the canon of musical theatre repertoire. The project is intended to be a teaching tool for advanced collaborative pianists working with advanced musical theatre singers, as many of the techniques create virtuosic piano writing and are designed for use with little to no prior rehearsal, which could potentially distract, rather than benefit, a beginning singer. The ultimate aim of enhancing the piano-vocal score is for the finished product to be creative and inspiring. Further objectives include: the creation of orchestral textures, allowing the singer more freedom, the creation of a piano part that is technically rewarding, and piano writing that inspires the singer. Through my descriptions of the techniques and discussions of the piano-vocal score enhancements, I hope to demonstrate that the singer, pianist, and audience all benefit when collaborative pianists enhance the piano-vocal score of musical theater repertoire.