Our music culture demands that we plan, practice, and master the performance of music perfectly. Improvisation, the art of dealing with unplanned and unpredictable musical situations, challenges this notion. Those who engage in it experience a cosmos of creative moments, where music becomes something entirely unique. Beyond purely style-specific improvisation guides and methods, this book describes the general prerequisites that underlie intense and high-quality improvisation. The focus is on improvisation as a play with the unforeseen and unheard. Learning to improvise can only succeed if rehearsals or lessons are designed appropriately for improvisation. Therefore, this book presents considerations on lesson design, teaching competence, and ensemble dynamics.