In November's installment of the Guest Room Sessions, singer-songwriter Matt Haeck and his special guest Megan Palmer team up to perform a cover of Gram Parsons’ “Return of the Grievous Angel," a song from Parsons' second, and final, album, Grievous Angel.

Filmed in the shower at Palmer’s home (bathrooms have great acoustics, after all!), Haeck and Palmer's rendition of "Return of the Grievous Angel" showcases their killer harmonies. Haeck plays guitar, Palmer plays the fiddle, and the result is pretty much magic.

“I love Gram Parsons. So much so that I have a very prominent tattoo of the Sweetheart of the Rodeo album cover,” says Haeck, explaining why he chose this particular track. “If you ask me, the Byrds were at their finest with Gram in the band.”

But this performance of "Grievous Angel" also has special significance for Haeck and Palmer, whom Haeck calls "one of the strongest women I know." The musician recently had surgery for breast cancer, and when Haeck came to her house to film this clip, "she was all smiles ... because the doctor had just cleared her to play violin again."

"It meant so much to me that she would honor me with her talent and her grace like this after the journey she’s been through," Haeck adds.

Haeck’s debut EP, Late Bloomer, was released back in June and is available via iTunes.