What is a DLS file? A DLS file contains a collection of digital instrument sounds in the Downloadable Sounds (DLS) format, which allows software and hardware devices to load custom instrument sets for use in MIDI playback. It stores instrument samples such as pianos, drums, or strings, which are mapped to specific notes and velocities for playback.

More Information Software that supports the DLS format includes MIDI synthesizers, game engines, and music production tools that allow users to control or enhance audio playback. Musicians, composers, and developers may use DLS files to shape the sound of their MIDI compositions or game soundtracks. Some notable DLS files include Roland GS sound sets, which extend the General MIDI (GM) standard with additional instruments and effects. These files enable MIDI sequences to produce more realistic or customized audio output by replacing the default system sounds with higher-quality samples. NOTE: The Interactive Audio Special Interest Group (IASIG) initially developed the DLS format, basing it in part on the Interactive Music Architecture used by Microsoft and other audio platforms. The MIDI Manufacturers Association (MMA) continues to develop the format.