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 MaThere are limits to how much sound a cello can make. That's part of the framing of acoustical instruments. Finding what those limits might be, and then trying to suggest perhaps even the illusion of going beyond is part of that kind of effort.
Yo-Yo Ma