Members of the National and Grizzly Bear unite for an ornate cover of the Grateful Dead’s symphonic-prog suite, “Terrapin Station.” The 17-minute all-star epic highlights Day of the Dead, a 59-track Grateful Dead tribute LP also featuring the Flaming Lips, Wilco with Bob Weir, Jenny Lewis, Jim James, Bon Iver’s Justin Vernon and Mumford & Sons,…