Yes, you are on the right blog. This is Totally Covered, not Wicked Guilty Pleasures.
When I first heard this song:
1. I thought it was boring.
2. I thought the whole cup thing was stupid.
You aren't going to change my mind on #2, but my mind was recently changed on #1. The song was written by A.P. Carter - you know, of the Carter Family - in 1931 and recorded by Carter Family. Even this version - complete with cups - is a cover, done in 2009 by Lulu and the Lampshades.... in two part harmony.
But this version is simple and reminiscent more of the original than the 2009 cover. (Or the cover by Anna Burden.....) The lyrics are heartbreaking, and Ms. Kendrick does them justice with her strong but simple rendition.
I still think the whole cup thing is stupid. But in this context, I guess it's ok. Here's the original scene from the movie.