The very best music takes you to a different place, a different headspace, to the one you’re in before you hear it. And on the Grateful Dead’s masterful 1969 live album Live/Dead, they grab the listener and pull them head-first into another dimension. You don’t have to be on drugs to enjoy this, but that’s not to say they didn’t need them to create it. The psychedelic era of the late 60s is a problematic time in music history. On the one hand, it saw a generation of talented people reach deep into themselves, and begin to push at boundaries and…