Until the beginning of the 20th century, the sub-discipline of "Tonsatz" had an immense and also international impact within the discipline - at that time still under the name Theory of Music. Moritz Hauptmann, who has recently been intensively received again, taught here, as did E. Th. Fr. Richter and S. Jadassohn, whose practical orientation made Leipzig music theory known, especially in English-speaking countries. Hugo Riemann, the most important theoretician around 1900, was educated at the Leipzig Conservatory. His theories have been rapidly reformulated in America for about twenty years under the name Neo Riemannian Theory. Sigfrid Karg-Elert's eccentric and Hermann Grabner's teaching in the succession of Riemann have been formative after World War II in the one case for the East German area, in the other for the West German one. Researching this music theory (the theoretical history of one's own institution), which stands between philosophical and practical accentuation, developing it further and exploring its reception in other countries offers interesting tasks especially for the major subject teaching.
A special feature of the compulsory subject education is its orientation towards practical work, towards making music. This is ensured by teaching in small groups of two to three students.
The subject of composition offers opportunities for a variety of collaborations with other disciplines.
An example of a cooperative project was the performance of an operetta for children, "Die kleine Aehrenleserinn" by J.A. Hiller, orchestrated and arranged by school music students and one major. For a workshop performance, the instrumentalists and students from other disciplines (dramaturgy/directing, conducting, and singing (for the children's vocal pedagogy)) worked together with students and teachers from the Thomas School.
Other examples are the cooperation with the Music Department of the Sorbonne on the topic "compositrices et interprètes en France et en Allemagne", a research project (2017-19) that included a total of nine conferences, and currently the cooperation with the Musicology Institute of the University of Basel and the Institute for Composition, Electroacoustics and Tonmeister-Education at the University of Music and Performing Arts Vienna on the topic "Salon Orchestra in the Engadine", a project to which the theory classes from Leipzig and Vienna contribute new arrangements.
