A new song by Sinéad O'Connor features in the movie Wild Mountain Thyme, which was filmed in Co Mayo.
Director John Patrick Shanley announced the news on Twitter, saying he has always been a "big admirer" of the singer.
"I have been thrilled by a turn of events, which is that Amelia Warner and I wrote a song that Sinéad O'Connor decided to record," he said.
"It's in the final credit roll of the film and it's quite beautiful.
"I didn't see that coming, but I've always been a big admirer of Sinéad. It's really nice to have her lend her voice."
The original song is called I'll Be Singing and will play at the end of the movie.
The film is based on Shanley's play Outside Mullingar. He said it relates to his experience growing up in the midlands.
Shanley also wrote Moonstruck (starring Cher and Nicolas Cage), which won him a Best Original Screenplay Oscar in 1988.
Wild Mountain Thyme, which features Emily Blunt, Jamie Dornan, Jon Hamm and Christopher Walken, received much criticism over the actors' Irish accents in the trailer.
Many people took to Twitter to share their views, with one viewer writing: "I saw the trailer for Wild Mountain Thyme and I have never been so baffled by a movie trailer in my life.
"Is it a comedy? Is it set in 1960 or 2020? Why is Emily Blunt's accent so baffling?"
However, the locals in Crossmolina, Co Mayo, where much of the film was shot, are excited about it.
Eamon Moore, who runs The Thatch Inn, where Emily Blunt was pictured pulling her first pint of Guinness, said the critics have got it wrong.
"We can talk about the accents, but the simple fact is the audience that film is geared towards isn't Irish people," he said.
"It's targeted at America or Europe or Asia, where Jamie Dornan is absolutely massive."