Prof. Thunemann begins the masterclass noting that, regarding the tempo, the students must play thinking in the biggest unit, not in the smallest one. Even though the tempo is Largo, it is in 4 (not in 8 or 16), otherwise the music becomes very boring. The bass line provides the tempo.
Besides, the professor gives other musical indications about phrasing, rhythm and articulation, and he insists on the importance of improving the tempo for their performance.