That was the punch line of what is likely an apocryphal story about an interaction between the great German conductor Otto Klemperer and an Italian principal oboe. Sadly, Klemp is not alone.
It must be hard to be a conductor, and I don’t mean that sarcastically. But one of the hardest things - judging by how few conductors have mastered it - is the art of not saying too much. No doubt the tradition (or myth) of the omniscient maestro, teaching the ignorant and faceless mass of musicians in front of him about the greatness of the art and getting them to play far beyond their innate musicality, is the source of much of the problem. Teaching involves a lot of talking, after all.
But that’s not really what happens with a professional orchestra. Generally they don’t need to be taught about the music. What they need is to be coordinated with each other so as to make the music sound the way the conductor wants it to sound. That can mean a lot of rehearsing and fixing things. The amount of words needed to rehearse and fix things can be surprisingly small, though.
One of the best examples I ever saw of this was back in my SPCO days. We had a guest conductor, Kazuyoshi Akiyama, and we were doing the Saint-Saens concerto with Ralph Kirshbaum. At one point in the rehearsal, Kirshbaum stopped and said something very quietly to Akiyama about how he wanted a particular wind passage to be phrased. I know he said it too quietly for the winds to hear because I was sitting principal viola (in those days, we sat on the outside) and could barely hear what he said from where I sat. Akiyama nodded, said “Letter A” or the equivalent, and began again. This time, with no verbal prompting and no guidance from the conductor at all except what he did with his hands, the winds did exactly what Kirshbaum had asked for.
That’s conducting. Now of course not all problems will be able to be solved that non-verbally. Often musicians need to be told what they’re doing that’s not working, especially when it’s a technical issue. But the telling does not need a lot of words. And letting the musicians know whether or not the problem is fixed doesn’t need a lot of words either.
If I were teaching conducting, I would require students to do the equivalent of language immersion - which, for conductors, would be not using words at all, except perhaps “start at bar X.” If I was feeling kind, I’d also allow “not together,” “flat” and “sharp.”
In my view, anything beyond that ought to be superfluous.