Madam Gorski uses a reel-to-reel audio tape deck to play music for the girls to dance as she encourages the girls to free their minds and lose themselves in their performances.
In the brothel reality, Madam Gorski uses the reel-to-reel to play music for the girls as they rehearse their dance numbers, which are intended to be a reflection of their individual personalities. The deck sits on a wheeled cart and is moved from the dance studio to Gorski's office to the Paradise Theater as needed. This deck is the main source of music in the brothel, but not the only one. (See Radio)
Blondie is seen wrapping up the tape deck's cord at the end of a rehearsal, but no one else touches the device.
In the real world, the reel-to-reel is spotted in Dr. Vera Gorski's office while Babydoll is having a therapy session with her, suggesting that perhaps Dr. Gorski records her sessions with the Lennox House patients.