diff --git a/src/frameworks/CoreMIDI/include/CoreMIDI/MIDIServices.h b/src/frameworks/CoreMIDI/include/CoreMIDI/MIDIServices.h
index 933beff70..a55d82e1d 100644
--- a/src/frameworks/CoreMIDI/include/CoreMIDI/MIDIServices.h
+++ b/src/frameworks/CoreMIDI/include/CoreMIDI/MIDIServices.h
@@ -3,9 +3,80 @@
 
 #include <CoreFoundation/CoreFoundation.h>
 
-extern const CFStringRef kMIDIPropertyName;
-extern const CFStringRef kMIDIPropertyConnectionUniqueID;
-extern const CFStringRef kMIDIPropertyUniqueID;
+/* Identification */
+extern const CFStringRef kMIDIPropertyName                        API_AVAILABLE(macos(10.0));
+// extern const CFStringRef kMIDIPropertyModel                       API_AVAILABLE(macos(10.0));
+// extern const CFStringRef kMIDIPropertyManufacturer                API_AVAILABLE(macos(10.0));
+extern const CFStringRef kMIDIPropertyUniqueID                    API_AVAILABLE(macos(10.0));
+// extern const CFStringRef kMIDIPropertyDeviceID                    API_AVAILABLE(macos(10.0));
 
+/* Capabilities */
+// extern const CFStringRef kMIDIPropertySupportsMMC                 API_AVAILABLE(macos(10.2));
+// extern const CFStringRef kMIDIPropertySupportsGeneralMIDI         API_AVAILABLE(macos(10.2));
+// extern const CFStringRef kMIDIPropertySupportsShowControl         API_AVAILABLE(macos(10.4));
+
+/* Configuration */
+// extern const CFStringRef kMIDIPropertyNameConfigurationDictionary API_AVAILABLE(macos(10.15));
+// extern const CFStringRef kMIDIPropertyMaxSysExSpeed               API_AVAILABLE(macos(10.0));
+// extern const CFStringRef kMIDIPropertyDriverDeviceEditorApp       API_AVAILABLE(macos(10.3));
+// extern const CFStringRef kMIDIPropertyNameConfiguration           API_AVAILABLE(macos(10.2)); // @deprecated at macos >= 10.15 && ios >= 13.0
+
+/* Presentation */
+// extern const CFStringRef kMIDIPropertyImage                       API_AVAILABLE(macos(10.2));
+// extern const CFStringRef kMIDIPropertyDisplayName                 API_AVAILABLE(macos(10.4));
+
+/* Audio */
+// extern const CFStringRef kMIDIPropertyPanDisruptsStereo           API_AVAILABLE(macos(10.2));
+
+/* Protocols */
+// extern const CFStringRef kMIDIPropertyProtocolID                  API_AVAILABLE(macos(11.0));
+
+/* Timing */
+// extern const CFStringRef kMIDIPropertyTransmitsMTC                API_AVAILABLE(macos(10.2));
+// extern const CFStringRef kMIDIPropertyReceivesMTC                 API_AVAILABLE(macos(10.2));
+// extern const CFStringRef kMIDIPropertyTransmitsClock              API_AVAILABLE(macos(10.2));
+// extern const CFStringRef kMIDIPropertyReceivesClock               API_AVAILABLE(macos(10.2));
+extern const CFStringRef kMIDIPropertyAdvanceScheduleTimeMuSec    API_AVAILABLE(macos(10.0));
+
+/* Roles */
+// extern const CFStringRef kMIDIPropertyIsMixer                     API_AVAILABLE(macos(10.2));
+// extern const CFStringRef kMIDIPropertyIsSampler                   API_AVAILABLE(macos(10.2));
+// extern const CFStringRef kMIDIPropertyIsEffectUnit                API_AVAILABLE(macos(10.2));
+// extern const CFStringRef kMIDIPropertyIsDrumMachine               API_AVAILABLE(macos(10.2));
+
+/* Status */
+// extern const CFStringRef kMIDIPropertyOffline                     API_AVAILABLE(macos(10.1));
+// extern const CFStringRef kMIDIPropertyPrivate                     API_AVAILABLE(macos(10.2));
+
+/* Drivers */
+// extern const CFStringRef kMIDIPropertyDriverOwner                 API_AVAILABLE(macos(10.1));
+// extern const CFStringRef kMIDIPropertyDriverVersion               API_AVAILABLE(macos(10.2));
+
+/* Connections */
+// extern const CFStringRef kMIDIPropertyCanRoute                    API_AVAILABLE(macos(10.0));
+// extern const CFStringRef kMIDIPropertyIsBroadcast                 API_AVAILABLE(macos(10.2));
+extern const CFStringRef kMIDIPropertyConnectionUniqueID          API_AVAILABLE(macos(10.1));
+// extern const CFStringRef kMIDIPropertyIsEmbeddedEntity            API_AVAILABLE(macos(10.1));
+// extern const CFStringRef kMIDIPropertySingleRealtimeEntity        API_AVAILABLE(macos(10.2));
+
+/* Channels */
+// extern const CFStringRef kMIDIPropertyReceiveChannels             API_AVAILABLE(macos(10.0));
+// extern const CFStringRef kMIDIPropertyTransmitChannels            API_AVAILABLE(macos(10.2));
+// extern const CFStringRef kMIDIPropertyMaxReceiveChannels          API_AVAILABLE(macos(10.2));
+// extern const CFStringRef kMIDIPropertyMaxTransmitChannels         API_AVAILABLE(macos(10.2));
+
+/* Banks */
+// extern const CFStringRef kMIDIPropertyReceivesBankSelectLSB       API_AVAILABLE(macos(10.2));
+// extern const CFStringRef kMIDIPropertyReceivesBankSelectMSB       API_AVAILABLE(macos(10.2));
+// extern const CFStringRef kMIDIPropertyTransmitsBankSelectLSB      API_AVAILABLE(macos(10.2));
+// extern const CFStringRef kMIDIPropertyTransmitsBankSelectMSB      API_AVAILABLE(macos(10.2));
+
+/* Notes */
+// extern const CFStringRef kMIDIPropertyReceivesNotes               API_AVAILABLE(macos(10.2));
+// extern const CFStringRef kMIDIPropertyTransmitsNotes              API_AVAILABLE(macos(10.2));
+
+/* Program Changes */
+// extern const CFStringRef kMIDIPropertyReceivesProgramChanges      API_AVAILABLE(macos(10.2));
+// extern const CFStringRef kMIDIPropertyTransmitsProgramChanges     API_AVAILABLE(macos(10.2));
 
 #endif // __MIDIServices_h__
diff --git a/src/frameworks/CoreMIDI/src/MIDIServices.m b/src/frameworks/CoreMIDI/src/MIDIServices.m
index 1a2d648b5..83be599fd 100644
--- a/src/frameworks/CoreMIDI/src/MIDIServices.m
+++ b/src/frameworks/CoreMIDI/src/MIDIServices.m
@@ -1,5 +1,15 @@
 #import <CoreMIDI/MIDIServices.h>
 
+// Note: It is expected for some of these values to be assigned `nil`,
+// Not sure why Apple doesn't actually assign a CFString value to these 
+// variables...
+
+/* Identification */
 const CFStringRef kMIDIPropertyName = nil;
-const CFStringRef kMIDIPropertyConnectionUniqueID = nil;
 const CFStringRef kMIDIPropertyUniqueID = nil;
+
+/* Timing */
+const CFStringRef kMIDIPropertyAdvanceScheduleTimeMuSec = nil;
+
+/* Connections */
+const CFStringRef kMIDIPropertyConnectionUniqueID = nil;