Yesterday a small group of amateur singers sight-read a Mozart four-part canon V'amo di core, which I had never sung before, though it has called out to me for many years. It turns out to be all about tenderness. And so it is, every note. The point is made right away with the first deviation from the obviously tunable notes of the tonic triad. He makes them risky in the most beautiful way.
I woke up this morning realizing how easily such fragile music gets destroyed by banging out the right notes on the piano rather than allowing (encouraging!) singers to puzzle out the emotional distances between pitches. It makes all the difference in the world.