In an interview with Variety, Hawke and Nivola said they hoped to achieve a music term called “blood harmony” in their performances. It’s a term that describes the kind of harmonizing that can be achieved when family members sing together, because their genetic link allows them to share the same tone in their voice.
“It’s such an important expression to us,” said Hawke. “It sounds both violent and beautiful and the music should be that. It’s aggressive, it’s electric, it’s strange. It’s not Brooklyn folk rock. It’s not wannabe cool guy country. It’s hillbilly gospel music.”
The film will be directed by Phil Morrison,