Peter Gallagher on that tear-jerker 'Zoey's Extraordinary Playlist' finale

Spoiler alert: This story contains details from the season finale of NBC's "Zoey's Extraordinary Playlist." 

The tragic ending "Zoey's Extraordinary Playlist" fans were expecting all season long finally transpired, but that didn't make it any less heartbreaking. 

Characters on NBC's musical dramedy "Zoey's" said a tearful (and musical) goodbye to patriarch Mitch Clarke (Peter Gallagher) in Sunday's finale  after a first season that chronicled a family's ups and downs, as Gallagher's character increasingly struggled through a battle with progressive supranuclear palsy. 

"Whatever they may have anticipated about the show, I think we surprised you. And even knowing that the finale was going to be possibly moving, I think we surprised you," Gallagher tells USA TODAY on Monday. ""I'm very happy to have been a part of 'Zoey's Extraordinary Playlist' and have it come out during this time. I can't believe how many people have suffered with the kind of disease," including the father of series creator Austin Winsberg, to whom the episode was dedicated.

"It's moving to me to see how many people have family members or just people who have lost parents or lost somebody and are gratified that we've done our job well enough that what we've shown, they recognize and it resonates with their own experiences. To be able to be a part of a story like that at a time like this, I couldn't feel luckier in that way," Gallagher says. 

Staying Apart, Together:A newsletter about how to cope with the coronavirus pandemic

Jane Levy as Zoey Clarke and Peter Gallagher as Mitch dance together in the "Zoey's Extraordinary Playlist" season finale.

The sob-inducing finale lets viewers in as Zoey (Jane Levy); mother Maggie (Mary Steenburgen); brother David (Andrew Leeds) and his wife, Emily (Alice Lee) share their last moments with Mitch.

And as always, characters' feelings are expressed through song: Mitch says a farewell to his family with Billy Joel's "Lullabye." He and Zoey share a last dance to an instrumental version of "True Colors." And funeralgoers perform an ensemble rendition of Don McLean's "American Pie" as a finale.

"The challenge was what was going to be the last moment with (Zoey)? We were talking about songs, I was pitching (Neil Diamond's) 'Holly Holy,' " says Gallagher, who like other cast members has a background in musical theater. "Austin envisioned that moment for Mitch helping Zoey be distracted from the more painful parts of watching someone you love die. And I just loved that idea." 

"You're always going to hear me, whether it's a song or not," Mitch tells Zoey in his final moments. "All you have to do is listen." 

Review:NBC's musical 'Zoey's Extraordinary Playlist' will make you wanna dance with somebody

Gallagher treated his role as an homage to his late mother, who had suffered from Alzheimer's. He said it was "powerful to sort of connect with her" through the character: "As soon as I read Austin's script, I was so grateful that he wrote it. And so grateful that he wanted me to be part of it."

Yet the actor "never really anticipated that it would succeed" – he likens an original musical succeeding to a unicorn, but thought the idea of implementing an ultimate playlist of hit songs was a "game changer." 

"I thought it was such a powerful story," Gallagher says. "It was a story in these divisive, confrontational and combative and mistrustful times – I thought it was really powerful to be telling a story about all the things that connect us and all the things we share, regardless of what you look like or where you're from... The only requirements for admission are to be part of the human race." 

Alice Lee as Emily, Andrew Leeds as David Clarke, Mary Steenburgen as Maggie Clarke and Jane Levy as Zoey Clarke mourn Mitch in the "Zoey's Extraordinary Playlist" season finale.

At some point this month, TV executives will decide whether "Zoey's" will get the green light for Season 2, Even with Mitch's passing, is there a possibility that a second season could mean more work for Gallagher? 

"Who knows," he teases. "I mean, we're making it all up anyway. I would love to come back. I would just hope Austin doesn't have me doing anything that'll make the audience wish I was dead again. So I'm good for whatever it is, as long as I'm not sullying Mitch's memory."

He adds: "Having a show that works is miraculous. It's all about at-bats. So that creates a little tension because you think, 'Oh, great. When's the next time I'm going to be in a show this good?' But I'm just really grateful I had a chance to be part of it."