A PPI file is a pack installation file used by Yamaha PSR keyboards, such as PSR-S670 or PSR-S970. It contains one or more expansion packs, which are used to extend the functionality of keyboards. PPI files are typically used to add instruments, voices, and styles to a Yamaha keyboard.

PPI files are meant to only be installed on a Yamaha, and cannot be opened on a computer. You can manage PPI files using Yamaha Expansion Manager, which is available for Windows and macOS. To transfer PPI files from a computer to a keyboard, move the PPI file to a USB flash drive, then insert the drive in the keyboard. When you install the PPI file on the keyboard it erases any expansion packs currently installed on the keyboard.