An RTI file contains an instrument used by Raster Music Tracker, a program used to create Atari XE/XL music in Windows. It stores information about the instrument, including the type, name, how many times it is used, and which notes it plays. RTI files allow users to share instruments and use them in different songs.

You can open an RTI file in Raster Music Tracker by selecting Instrument → Load and paste to actual instrument.. You can create an RTI file in Raster Music Tracker by selecting Instrument → Save actual instrument as.... NOTE: Raster Music Tracker enables Windows users to emulate the capabilities of the 1979 Atari POKEY sound chip used in Atari 8-bit home computers and Atari arcade games in the 1980s.