Over the 20+ year history of Hardly Strictly Bluegrass more than 1,500 artist have joined us in Golden Gate Park. Many of these performances were recorded. Portals to the Past is our way of sharing some of our favorite highlights from the archives. Episode 2 contains some of the most special duets and collaborations that we have captured over the years including Guy Clark and Verlon Thompson, First Aid Kit, John Prine with Kurt Vile, Gillian Welch and David Rawlings, Marcus Mumford and Danielle Ponder, and Merle Haggard with Kris Kristofferson.