Old & In The Way: Midnight Moonlight
Some bluegrass records are more welcoming than others; the Old & In The Way record is like bluegrass bait for deadheads. Here's the scoreboard: Jerry Garcia, David Grisman, Vassar Clements, Peter Rowan, and John Kahn on bass. Definitely one of the first I would recommend, then it's just one more step to Muleskinner, the fascinating guitar work of Clarence White, the KY Colonels, then it's on to Doc, Bill, Ralph, and you're in for life.
This Peter Rowan tune has always been a favorite, one of the first that got me hooked.