int speakerPin = 0;
char c;
int ton =0;
int tones[] = { 1136, 1014, 1915, 1700, 1519, 1432, 1275 };
int tempo = 300;
void setup() {
 Serial.swap(1);
 Serial.begin(9600);

 pinMode(speakerPin, OUTPUT);

}

void loop() {
   while (Serial.available() > 0) {
           c= Serial.read();
  ton = c-96;
//          Serial.println(ton);
//    Serial.println(c);
    playTone(tones[ton-1], tempo);
}
}
void playTone(int tone, int duration) {
  for (long i = 0; i < duration * 1000L; i += tone * 2) {
    digitalWrite(speakerPin, HIGH);
    delayMicroseconds(tone);
    digitalWrite(speakerPin, LOW);
    delayMicroseconds(tone);
  }
}