Prior to the invention of sound recording, music was an art form that was realized exclusively through live performances. Once sound was recorded, it could be analyzed and dissected to the point of making one anal retentive. The Dead was the type of band you needed to hear live, in the 1960's, their period of gestation. You cannot replicate the live experience no matter how many bits your recording equipment samples. People have bandied about the term holistic to describe a lot of things in life. But there is something about the sound field in a small club, with many people present, dancing, swinging, and even drinking, that constitutes the live experience of music. There is a principle in physics called superposition, which posits that you can individually add up the sound of each instrument, recorded in its own room or timeline, and that it is the same as what you would hear in a live setting (assuming you could dial in reverb, etc.). Total B.S. I will be the first to admit that the Grateful Dead are not one of the top 10, or 100, best bands of all time. But they were fine for the night, and even with Pigpen, they grooved, and made the audience happy. The day people begin critiquing rock bands like an academic music professor is the day people lose sight of what music is really for. It is for the ear(s) of the beholder.
The appeal of "jam bands" is that every time they get up to play, nobody - not even the band - really knows what's going to happen. Sure, some songs are generally pre-set and dialed-in, but in many cases, it's more like... "We know where we want to go, but we just don't know - or care - how long it takes us to get there. Let's take a journey."
I've heard about a half-dozen live versions of this song, and each one is different. Some are around 4 minutes, this one clocks in at over 10.