Whiplash is a critically acclaimed film directed by Damien Chazelle, released in 2014. The film follows the story of a young drummer, Andrew Neyman (played by Miles Teller), who enrolls at a prestigious music conservatory to study under Terence Fletcher (played by J.K. Simmons), a demanding and abusive instructor. The film features several scenes set in a jazz club, one of which shows Fletcher playing the piano.
Regarding the question of whether J.K. Simmons was really playing the piano in the jazz club scene, sources state that the actor did perform his own piano playing in the film. J.K. Simmons is a multi-talented actor who has a background in music, and he reportedly spent several months preparing for his role in Whiplash by practicing the piano.
In an interview with Rolling Stone, J.K. Simmons stated that he had a musical background and took piano lessons as a child. He also revealed that he spent several months preparing for his role in Whiplash by practicing the piano. He stated, "I wanted to be able to play credibly, even though I'm not a virtuoso. I wanted to be able to play things that were challenging and looked difficult but were actually within my abilities."
Furthermore, sources state that the film's director, Damien Chazelle, was intent on having J.K. Simmons perform his own piano playing in the film, as he believed it would add authenticity to the scenes and help bring out the character of Terence Fletcher.
In conclusion, based on the information from various sources, it can be confirmed that J.K. Simmons did indeed perform his own piano playing in the jazz club scenes in Whiplash. The actor's preparation and dedication to the role, combined with the director's vision for authenticity, helped to bring the film to life and contribute to its success.