const int speakerPin = 10;
int val;
const int potPin = A0;



void setup() {       
}
void loop() {
 val = analogRead(potPin);

int i = 0;
  for (i < val; val+450 > i ;i++) {
    tone(speakerPin, val+i);
  }

 for (i > val; val-450 < i ;i--) {
    tone(speakerPin, val+i);
  }
}