Last week you had Gillian Welch (and her partner, David Rawlings) backing up the Decemberists. Now they have top billing. s
This is where this theme can easily break down. Welch and Rawlings usually work together and alone. They usually play all their own instruments and do all vocals by themselves.
The closest I'm getting to a collaborator here is T-Bone Burnett who produced their first two disks and plays on them.
So coming from Welch's debut disk back in 1996, Revival, here is "Paper Wings".