procedure GetMIDIOutDevices(Devices: TStrings);
 var
 i, DNum: Integer;
 Caps: TMIDIOUTCAPSA;
 begin
 DNum := MIDIOutGetNumDevs; // Number of Devices 
 for i := 0 to DNum - 1 do // Query Devicenames 
 begin
 MIDIOutGetDevCaps(i, @Caps, SizeOf(TMIDIOutCapsA));
 Devices.Add(string(Caps.szPname));
 end;
 end;

 // Usage: 

var
 MIDIDevices: TStringList;

 begin
 MIDIDevices := TStringList.Create;
 try
 GetMIDIOutDevices(MIDIDevices);
 // Do anything with the device name list 
 finally
 MIDIDevices.Free;
 end;
 end;