When talk show bands play an impromptu song, how do instantly play in the same key?

Question

When talk show bands play an impromptu song, how do instantly play in the same key?

In: Other

Answer 1

This is a great example of what I mean . . . Bette Midler and Johnny Carson start singing Rainy Day acapella, and then the pianist comes in after several seconds, so they’ve already established their pitch. But the pianist is dead on.

I would be scared shitless to start playing after someone is already singing . . .

But I also know the Johnny Carson band was the highest echelon of musicians.

[https://www.youtube.com/watch?v=tAuUGNs0oH0](https://www.youtube.com/watch?v=tAuUGNs0oH0)