Original Cast Recordings (OCRs) of musical theatre are an important yet understudied aspect of popular music and musical theatre scholarship. This proposal explores the sonic and musical dimensions of OCRs through the lens of digital musicology (DM), a field that combines traditional musicology with computer science, statistics, and other quantitative disciplines to explore questions related to music and its creation, distribution, reception, and impact. Through the use of DM tools and techniques such as musical feature extraction, music information retrieval and machine learning, this presentation examines OCRs as sonic artefacts to reveal the musical and performative nuances of OCR performances. Digital musicology offers new ways of understanding and appreciating musical recordings by combining traditional musicology with cutting- edge computational methods, offering a fresh perspective with potential to shed new light in this area. The scale offered by computational analysis facilitates the analysis of a wide range of recordings across the history of OCR and enables comparisons between OCR and other recordings. This approach fits within the broader aims of the conference by exploring the art, artefact, and analysis of these fascinating, complex, and culturally vital recordings, the interdisciplinary approach helps support links between musical theatre scholarship, digital musicology and popular music studies. We hope to contribute to a better understanding of OCRs as rich and complex sonic artefacts that are worthy of study and appreciation and uncover new insights into the history and cultural significance of original cast recordings through the application of these analysis techniques.