Practicing is not only playing your instrument, either by yourself or rehearsing with others - it also includes imagining yourself practicing. Your brain forms the same neural connections and muscle memory whether you are imagining the task or actually doing it.
Yo-Yo MaIn performance, we have a greater purpose. The greater purpose is that we're communing together, and we want this moment to be really special for all of us. Because otherwise, why bother to have come at all? It's not about proving anything. It's about sharing something.
Yo-Yo Ma