Mastering for music in stereo in 2024. What are the real objectives of this discipline today? What are the axioms of this practice? And what is a typical modern processing chain made of? When and why do I need to do A/B comparisons? What does QC stand for? What types of processors are normally used and how? When and how to apply dither to a music program? What format and resolution should the mastering engineer work at? At which format and resolution should the mixing engineer deliver the final work? How loud should the final mixes be and why doesn't it really matter? These and other issues will be addressed in this tutorial.