Take a master of their art, and let them be coached, for an hour, by a grandmaster. In public, with everybody there to listen, learn and be amazed. That is a masterclass in a nutshell.
Wikipedia claims that masterclasses exist in “painting, drama, any of the arts, or on any other occasion where skills are being developed.” But I have never seen them being effective except in classical music. There, they can be absolutely amazing.
Case in point. A month ago I did not even know of the existence of Benjamin Zander, who turns out to be a very accomplished cellist and conductor with a long career. By accident, I came across a series of masterclass recordings on Youtube that he had tought with various, mostly chamber, music groups. And I’ve been glued to them ever since.
Some of the music produced during his masterclasses is better than anything available on professional recordings, regardless of their fame. Take this particular part of a session on Elgar’s Cello Concerto. Fast forward to 9min 45sec:
The gold standard for the performance of this piece is Jaqueline du Pre’s 1965 recording with Barbirolli, and that is indeed much better than any other recording I’m aware of. But some of what Zander inspires cellist Daniel Hass to do here surpasses the gold standard. And the commentary, and the teaching, and his being, are just marvelous.
As he says, such a joy.