The new teaching material for secondary education I follows a new concept of music education: the principle of progressive learning in music. Musical skills are practically acquired in their entirety and are closely intertwined with the exploration of cultural contexts. The new textbook aims to provide students from grade 5 with a systematic approach to music, offering many practical practice opportunities and enjoyment in their own musical practice. This new textbook is designed for gymnasiums, comprehensive schools, and secondary schools! The starting point: progressive learning in music. MusiX represents a paradigm shift: moving away from a content-oriented textbook often used as a "quarry" towards a course book that is based on the principles of progressive music education. Meaningfully sequenced learning steps lead to the development and consolidation of music.