Fingers

Fingers is a 1978 drama film directed by James Toback.
The film features Harvey Keitel as a pianist who also works for his loan shark father as a "collector". He is a conflicted soul, torn between his art, his loyalty to his father, his sexuality, and his past. [Wikipedia]

Really good movie which was readapted by Jacques Audiard in the also brilliant "De battre mon cœur s'est arrêté" ("The Beat That My Heart Skipped" in english) starring Romain Duris.