piano code multibuttoned partial array

const int channel = 1; // global midi channel
const int buttonPinL = 3; // set array rows with easy naming
const int buttonPinR = 2; // set array colums with easy naming

int buttonPin[buttonPinL][buttonPinR] = {
  {0, 3}, // 1.65v comparaor threshold buttons
  {1, 4}, // 3.3v comparator threshold buttons
  {2, 5} // damper off buttons
};

volatile unsigned long time1 ; // 1.65v comparaor timing
volatile unsigned long time2 ; // 3.3v comparaor timing
volatile unsigned long timePassed1;
volatile unsigned long time3 ;
volatile unsigned long time4 ;
volatile unsigned long timePassed2;

volatile boolean valid1 = false ;// timing debounce
volatile boolean valid2 = false ;
volatile boolean valid3 = false ;
volatile boolean valid4 = false ;

float maxVelocityTime = 30000; // my slowest amount of time passed between 1.65 and 3.3v threshold

int velocity1;
float velocityFloat1;
float velocityFloatCorrected1;
int velocity2;
float velocityFloat2;
float velocityFloatCorrected2;

void int1 () // ISR for threshold time stamps 1.65v
{
  if (!valid1)
  {
    time1 = micros () ;
    valid1 = true ;
  }
}

void int2 () // // ISR for threshold time stamps 3.3v
{
  if (valid1 && !valid2)
  {
    time2 = micros () ;
    valid2 = true ;
  }
}

void int3 ()
{
  if (!valid3)
  {
    time3 = micros () ;
    valid3 = true ;
  }
}

void int4 ()
{
  if (valid3 && !valid4)
  {
    time4 = micros () ;
    valid4 = true ;
  }
}

void setup ()
{ for (int j = 0; j < buttonPinL ; j++) {
    for (int i = 0; i < buttonPinR ; i++) {
      pinMode(buttonPin[j][i] , INPUT_PULLUP);

    }
  }
  attachInterrupt (buttonPin[0][0] , int1, RISING) ;
  attachInterrupt (buttonPin[0][1] , int3, RISING) ;
  attachInterrupt (buttonPin[1][0] , int2, RISING) ;
  attachInterrupt (buttonPin[1][1] , int4, RISING) ;

}
void loop () {
  byte button2;
  byte button5;
  button2 = digitalRead(buttonPin[2][0]);
  button5 = digitalRead(buttonPin[2][1]);

  if (valid2) // when both thresholds are proven process note
  {
    timePassed1 = (time2 - time1);
    Serial.println (timePassed1) ;

    velocityFloat1 = 127 * maxVelocityTime / timePassed1;
    if (velocityFloat1 > 127)
    {
      velocity1 = 127;
    }
    else
    {

      velocityFloatCorrected1 = sqrt(127 * velocityFloat1);
      velocity1 = velocityFloatCorrected1;
    }
    usbMIDI.sendNoteOn(62, velocity1, 1);

    noInterrupts () ;
    valid1 = valid2 = false ;
    interrupts () ;
  }
  if (button2 == LOW) {
    usbMIDI.sendNoteOff(62, 0, 1);

  }

  if (valid4)
  {
    timePassed2 = (time4 - time3);
    //Serial.println (timePassed2) ;

    velocityFloat2 = 127 * maxVelocityTime / timePassed2;
    if (velocityFloat2 > 127)
    {
      velocity2 = 127;
    }
    else
    {

      velocityFloatCorrected2 = sqrt(127 * velocityFloat2);
      velocity2 = velocityFloatCorrected2;
    }
    usbMIDI.sendNoteOn(65, velocity2, 1);

    noInterrupts () ;
    valid3 = valid4 = false ;
    interrupts () ;
  }
  if (button5 == LOW) {
    usbMIDI.sendNoteOff(65, 0, 1);

  }
}