Essen Associative Code
The Essen Associative Code (EsAC) is probably the oldest, and certainly the longest-surviving, code for music in active use. Partly because of its longevity, this code forms the basis of hundreds of thousands of analogue (typescript) encodings in European archives. Only a small portion of this material is represented in the computer applications described below.
Origins and History to 1982
Strictly, the term "EsAC" pertains only to work done from 1982 onward. The antecedents of code can be trace back almost 200 years, although most of what survives today dates from after 1860. As the Hapsburg domains expanded in the eighteenth century the diversity of cultural communities became steadily broader. Near the end of the reign of the emperor Joseph II (1765-1790), an initiative to document the practices of these many communities was initiated. Music was one of those practices.
Through much of mid-to-late nineteenth century the collection of folksongs was vigorously pursued, not only in Austro-Hungary but in many neighboring states. Much attention was given in the early twentieth century to publication and codification. Inevitably these efforts raised many new questions: (1) Did folksongs with the same title have the same music? (2) Was the same text set to more than one tune? The answers were "Not necessarily" and "Often." With infinite patience the transcription of melodies together with basic information about title, location from which the music came, meter, and so forth was typed. These descriptions of single songs came to fill countless file drawers.
The most potent question that folksong researchers began to ask as they organized this growing body of material was: How does the process of "morphing" (change by slow degrees) work in folksongs? Can the pathways of changed be predicted? Can styles of adaptation be linked to certain regions? These open-ended questions proved difficult to answer. They continue to be asked today.
The development of personal recording devices since 1950 brought new possibilities to folksong research. The collation of data was not set aside, however.