Don't let the '76 fool ya. This is really a collection of unreleased material starting from the '67 "Nefertiti" sessions up to the "In a Silent Way" period, featuring the classic Miles Davis Quintet transitioning and cross pollenating with the eminent "Bitches Brew" crew. A great insight into a artist's process but then again Miles will always be Miles.
Its rumored that bassist Ron Carter left the group because of the addition of the electric instruments, i.e. the Fender Rhodes. No?