The role of a mastering engineer is fundamentally centered around the completion of the audio mastering process for an album. This process involves preparing and transferring the recorded audio from a source to a data storage device while optimizing sound quality and ensuring consistency across all tracks. The mastering engineer is responsible for finalizing the audio output, making adjustments to equalization, compression, and overall loudness to enhance the listening experience, and creating a cohesive sound that is suitable for distribution, whether it be for digital platforms, vinyl, or other formats.
In this context, other roles presented do not fall under the purview of a mastering engineer. Creating original music compositions refers to songwriting and composition work, which is distinct from the final stage of audio production. Duplicating CDs for sale is more aligned with manufacturing processes rather than the artistic audio refinement that mastering entails. Live sound engineering involves mixing audio during a live performance and is considerably different from the studio environment where mastering takes place. Thus, understanding the specific responsibilities associated with mastering helps clarify why completing the audio mastering process for an album is a primary function of a mastering engineer.