const int buzzerPin = 9;
const int songLength = 18;
char notes[] = "cdfda ag cdfdg gf "; // a space represents a rest
int beats[] = {1,1,1,1,1,1,4,4,2,1,1,1,1,1,1,4,4,2};
int tempo = 150;
const int button1Pin = 2; 
const int ledPin =  3;    // LED pin
void setup() 
{
  pinMode(button1Pin, INPUT);
  pinMode(buzzerPin, OUTPUT);
  pinMode(ledPin, OUTPUT); 
}

void loop() 
{
  int button1State; 
  button1State = digitalRead(button1Pin);
  int i, duration;
  
  if (((button1State == LOW))) // if we're pushing button 1  
  {
   
    digitalWrite(buzzerPin, HIGH);
    for (i = 0; i < songLength; i++) // step through the song arrays
      {
        digitalWrite(ledPin, HIGH); 
        duration = beats[i] * tempo;  // length of note/rest in ms
        
        if (notes[i] == ' ')          // is this a rest? 
        {
           
          delay(duration);            // then pause for a moment
        }
        else                          // otherwise, play the note
        {
          
          tone(buzzerPin, frequency(notes[i]), duration);
          delay(duration);            // wait for tone to finish
        }
        delay(tempo/10);              // brief pause between notes
         digitalWrite(ledPin, LOW); 
      }
  }
 
  
  
  
}

int frequency(char note) 
{
  int i;
  const int numNotes = 8;  // number of notes we're storing
  char names[] = { 'c', 'd', 'e', 'f', 'g', 'a', 'b', 'C' };
  int frequencies[] = {262, 294, 330, 349, 392, 440, 494, 523};

  for (i = 0; i < numNotes; i++)  // Step through the notes
  {
    if (names[i] == note)         // Is this the one?
    {
      return(frequencies[i]);     // Yes! Return the frequency
    }
  }
  return(0);  // We looked through everything and didn't find it,
              // but we still need to return a value, so return 0.
}