Some internal MIDI synthesizers support volume level changes and patch caching. Use the following functions to query and set the volume level and to cache and uncache patches with internal MIDI synthesizer devices:
midiOutCacheDrumPatches
Requests that an internal MIDI synthesizer device preload a specified set of key-based percussion patches.
midiOutCachePatches
Requests that an internal MIDI synthesizer device preload a specified set of patches.
midiOutGetVolume
Queries the current volume level of an internal MIDI synthesizer device.
midiOutSetVolume
Sets the volume level of an internal MIDI synthesizer device.