Jacob Collier, on YouTube:

A few months ago, I was challenged to improvise a piece of music with an orchestra, with no plan, no sheet music, no rehearsal, and no prior discussion. Here’s what happened.

Most of the praise for this improvised performance has landed on Collier for creating it, on the fly—and deservedly so!—but I’m equally impressed by the musicians, who, given little more than a handful of notes and a smattering of direction, responded with artistry and spontaneity to craft eighteen exquisite minutes of musical magic. A breathtaking blend of vision and virtuosity.