The Max Steiner Digital Thematic Catalog is an ongoing corpus study project which will eventually incorporate thematic data from all of Steiner’s film scores (over 31,000 pages of film sketches and 300+ films). This corpus is significant because Steiner’s work is representative of three decades of Classic Hollywood film scoring practices. Consistent metadata and tagging will help researchers to use this corpus efficiently. A tagging system has been developed to associate film events, places, and characters with musical cues. This tagging system will allow scholars to make comparisons between cues and to find patterns across Steiner’s massive corpus. An average film has over 1,000 tags and the process of tagging them will take over a decade. Thus, it is important to have a consistent tagging process with established procedures and categorization methods. In order to consistently tag the cues in a film, we have established specific tagging categories. The core tagging categories are mood/emotion, action, character, setting, and scene (MACSS). Additional categories include object tags, music tags, film tags, and analytical tags. In addition to these procedures, we have developed automated tools to ensure consistency. Most film tags (such as the tagging system found in IMDb) are associated with elements of the plot or with film genres. Our tagging system is specifically focused on film music analysis, which introduces numerous terms not found in typical tagging schemas or established thesauri. We believe this will be very useful to scholars in the growing field of film music research.