and This one is a nice intro to Bluegrass with Louvin Bros songs done by famous folks like Merle Haggard, James Taylor, Alison Kraus, Dollie Parton and others.

I would suggest going from those links and browse Amazon sample cuts from Bluegrass albums by people like Newgrass Revival, Flatt and Scruggs, The Stanley Brothers, Peter Rowan, Dillards, Alison Krauss and Union Station, Hoy Rize and Del McCoury. Check out some acquaintances of mine from here in Colorado The Blue Canyon Boys

I envy you discovering this amazing new world!