Leaving aside for a moment the issue of whether an unshown TV special from '68 could capture, as the opening credits suggest, "the spontaneity, aspirations and communal spirit of an entire era" any more accurately than, say, Catweazle or Do Not Adjust Your Set, and regardless of whether you think Beggars Banquet and Let It Bleed are the fulcrum points of a generation or just something that music critics of a certain age should learn to get over, the portents of this cryogenically preserved moment in rock time are undeniable. Look!