Still unable to send CC using MIDI Library

Other Hardware Audio
4

I would suggest declaring cc as

byte cc = 0;

because that is the expected type for the control value:

[

void MIDI_Class::sendControlChange 	( 	byte  	ControlNumber,
		byte  	ControlValue,
		byte  	Channel 
	)

16 (General Purpose Controller 1 ) looks like a reasonable choice of controller number. It is unlikely to be mapped to anything by default however.](Arduino MIDI Library: MIDI_Class Class Reference)