The American judiciary has played a pivotal role in delineating the scope of protection available under music copyright. In recent years, courts have increasingly recognised the need to limit copyright to genuine expressions of creativity, ensuring that fundamental musical elements remain within the public domain. This paper examines key decisions, including Williams v. Gaye and Ed Sheeran v Structured Asset Sales, which reflect a judicial shift towards safeguarding the commons of musical ideas. It argues that this recalibration is crucial for sustaining innovation and artistic freedom in the contemporary music industry. By analysing the evolution of legal doctrine and its broader policy implications, this paper outlines the trajectory of maintaining a balanced copyright system in the United States and how other jurisdictions can be influenced by this trajectory.