This site introduces unknown Emanuel Bach (C. P. E. Bach).
I asked ChatGPT4o: "Christian Bachʼs works have opus numbers, but were these assigned by him?"
Johann Christian Bachʼs works are assigned opus numbers, but these were not designated by Bach himself. Instead, they were systematized by later musicologists and publishers. Below is a detailed explanation of this process.
In the late 18th century, it was common practice for composers to assign opus numbers when publishing their works. However, these numbers were not based on a unified system. This was also the case for Johann Christian Bach, whose works published during his lifetime were given opus numbers by publishers, but these lacked a consistent and systematic structure.
To systematically organize Johann Christian Bachʼs works, later musicologists established a consistent opus numbering system. This effort was aimed at making the study and classification of Bachʼs works more accessible.
The most significant catalog of Johann Christian Bachʼs works was compiled by British musicologist Ernest Warburton. He systematically categorized Christian Bachʼs compositions and assigned opus numbers. This catalog greatly facilitated scholarly research on Bachʼs music.
In addition to Warburtonʼs work, various researchers and publishers have created different catalogs for Christian Bachʼs compositions. However, Warburtonʼs catalog remains the most widely accepted and utilized.
The opus numbers of Johann Christian Bachʼs works were not assigned by Bach himself but were primarily systematized by later musicologists and publishers. Ernest Warburtonʼs catalog, in particular, is widely recognized and serves as the standard reference for studying Bachʼs compositions.