Below are the locations of the music discs in Chapter 9 of Final Fantasy VII Remake!
Chapter 9
22. Cosmo Canyon
Purchase the disc for 50 gil from a vending machine located in the Collapsed Expressway – Large Cave-In. This disc will be after the second time you have to use a crane to transport Aerith to a ledge to drop down a ladder.
8. Under the Rotting Pizza
Interact with a Jukebox along a chain-linked fence behind the family hotel in southern Wall Market.
10. Honeybee Inn
Purchase the disc for 50 gil from the Pharmacy to the right of the neon bar in the square of Wall Market.
17. Farm Boy
Speak with the Cowgirl in front of Good Luck in the northwestern part of Wall Market. She will give you the disc!
29. The Midgar Blues
Speak to the Singer in Yoidore, which is located along the southwestern part of Wall Market, to obtain his disc.
26. Let the Battles Begin! – REMAKE
This disc is acquired during the dance tutorial in the Honeybee Inn before your appointment with Andrea. You will have to get 10 greats during the practice in order to unlock the disc. You can keep retrying by repeating the practice.
11. Don of the Slums
Purchase the disc for 50 gil from a vending machine in the Forbidden Room of Corneo’s Mansion after the story segment where Cloud and Aerith get gassed.