Joanna Newsom's appearance on "Portlandia" takes place during this week's episode, which airs on IFC on Friday night at 10. The scene features Newsom, Fred Armisen, and Carrie Brownstein as carefree flower children. Newsom plucks at her harp in the middle of a golden field while others tap tambourines and strum guitars. But the very Zen mood breaks when the trio are faced with the impossible task of packing Newsom's instrument into a tiny hatchback.
UPDATE: That is indeed Robin Pecknold of Fleet Foxes at the :15 mark.