Recently I started plowing through a bunch of YouTube prog-rock videos from the late ’60s and ’70s, amazed at the musicianship of the bands in live performances: here were Gary Brooker and B. J. Wilson of Procol Harum on piano and drums respectively playing “Pilgrim’s Progress,” there was Keith Emerson of The Nice rolling through his take on Bach’s Third Brandenburg Concerto on his Hammond in “Brandenburger.” Every note played was analog, on real physical instruments, with no digital fixes added.