The MIDI Mapper provides standard patch services for device-independent playback of MIDI files. Applications that use MIDI files for audio should use the MIDI Mapper. For information on the MIDI Mapper, see “The MIDI Mapper” in Chapter 4, “High-Level Audio Services.” For information on authoring device-independent MIDI files, see “Authoring MIDI Files,” also in Chapter 4.
To use the MIDI mapper, open it using the midiOutOpen function with the wDeviceID parameter set to the constant MIDIMAPPER. Then you can send it MIDI messages using midiOutShortMsg or midiOutLongMsg.