"How can I play cleaner - even cleaner?" This question occupies every demanding string player during their daily practice. A survey revealed that over 70 percent of a string player's practice time and attention is devoted to intonation. In this book, Gerhard Mantel provides background knowledge on the phenomenon of intonation and presents practical practice methods that go far beyond a simple, spontaneous determination of "too high - too low." The sometimes unconventional solutions enable every string player to find their individual path to optimal intonation and to overcome seemingly unsolvable problems when playing with other string players, wind players, or piano. The author places particular emphasis on approaching intonation playfully and using it purposefully for artistic expression. Gerhard Mantel is an internationally experienced cellist.