This Is Us: Here's the Sweet, Sentimental Song Rebecca Sings to Jack in the Season 2 Finale

The season two finale of This Is Us gave us quite a few beautiful, tear-jerking moments, one of them being a glimpse of what could have been between Jack and Rebecca Pearson. Fans were treated to a fantasy flash-forward in which Jack (alive, well, and gray-haired) and Rebecca renew their vows as part of their 40th anniversary celebration. After their ceremony, family and friends attend a reception for the couple, during which Rebecca (Mandy Moore) performs her and Jack (Milo Ventimiglia)'s "song." In case you were wondering what the song is (and why it's so special), we have some fun details.

The song Rebecca sings is called "Moonshadow" and was originally written and performed by Cat Stevens back in 1971. Featured on his album Teaser and the Firecat, the song has been lauded for its uplifting message (my own mom used to play it for me as a lullaby when I was young) and has a special significance for Jack and Rebecca as a couple.

We first heard the song in the season one finale, also titled "Moonshadow," which detailed the sweet story of how she and Jack first met in the mid '70s, as well as one of their most explosive arguments two decades later. Rebecca is performing it on stage as Jack first lays eyes on her in a bar (a bar he was about to rob, by the way), and the tune also has a special connection to the half-moon necklace that he gifts her after he promises to stop drinking. "I got a moon because of . . ." Jack says, which Rebecca finishes with: ". . . our song." Rebecca promised she would never take the pendant off, and she doesn't — even after Jack's tragic death and her remarriage to Miguel (Jon Huertas).

Fun fact: Mandy herself has been performing "Moonshadow" since long before she landed her role on This Is Us. She covered the song on her 2003 album Coverage, and you can watch her rendition of it from that same year below. Then, get the details on that other beautiful song you heard during the season two finale.

click to play video