In the first half of the 19th century, all newly established music education institutions of the conservatory type had to solve the problem of teaching content and the emergence of new textbooks for newly conceived music theory subjects that were supposed to summarize all the subject matter of the so-called compositional science. The article deals with the influence of contemporary aesthetic theories on the concept of these subjects: on the example of the Paris Conservatory and textbooks by Antonín Rejcha.