Tuner is a compelling crime drama thriller that explores the life of Niki White, a once talented pianist whose career ends when he develops hyperacusis, a condition causing extreme sensitivity to sounds. Forced to find new work, Niki becomes a piano tuner in New York under the mentorship of a veteran named Harry Horowitz. While his musical career fades, Niki discovers he can hear minute mechanical shifts in objects. This hidden talent leads him into the dangerous criminal world, where his precision becomes highly valued by criminals. 

As financial burdens escalate, Niki finds himself trapped in high-stakes situations that threaten his connection with a composition student named Ruthie.