I can't see how your first code that you posted does much of anything.
Your second code could be improved by modifying it to use state change detection.
Look in the examples in the digital tab for "statechangedetection". EDIT: USE the code that you got from the "bounce" example and add the state change detection method.
I reformatted your second code to make it easier to read. Make some changes and I will try to help you if you still have trouble.
//Button 1
int ledPin = 12; //led output
int buttonPin = 10; //button input pin
int buttonVal = 0; //variable for reading the button status
int buttonState = 0; //variable to hold the buttons current state
int bounceCheck = 0; //variable for debouncing
void setup() {
pinMode(ledPin, OUTPUT); //declare LED as output
pinMode(buttonPin, INPUT); //declare pushbutton as input
Serial.begin(31250); //MIDI communicates at 31250 baud
}
void loop()
{
////////////////////////////TOGGLE////////////////////////////////////
buttonVal = digitalRead(buttonPin); //read input value from button
delay(5); //wait 10ms
bounceCheck = digitalRead(buttonPin); //check again
if(buttonVal == bounceCheck)
{ //if val is the same then not a bounce
if (buttonVal == HIGH && buttonState == 1)
{ //check if the input is HIGH
digitalWrite(ledPin, HIGH); //turn LED OFF
midiOUT(0xC0, 0, 1); //Note ON (CH 1), C1, velocity 127
buttonState = 0;
}
if(buttonVal == LOW && buttonState == 0)
{
digitalWrite(ledPin, LOW); //turn LED ON
midiOUT(0xC0, 0, 0); //Note ON (CH 1), middle C1, velocity 0
buttonState = 1;
}
}
}
//////////////////////////////////YOUR FUNCTION/////////////
void midiOUT(char command, char value1, char value2)
{
Serial.print(command);
Serial.print(value1);
Serial.print(value2);
}