int pinscount = 8;
int pins[] = {2,3,4,5,6,7,8,9};
int buz=13;
void setup() {
for (int i=0; i<pinscount; i=i+1){
    pinMode(pins[i], OUTPUT);
    pinMode(buz, OUTPUT);
}
}
void loop() {
 for (int i=0; i<pinscount; i=i+1){ 
  tone(buz,4300);
  digitalWrite(pins[i], HIGH);
  delay(250);
  noTone(buz);
  digitalWrite(pins[i], LOW);
  delay(250);
 }
 for (int i=pinscount-1; 1>0; i=i-1){
  tone(buz,2000);
  digitalWrite(pins[i], HIGH);
  delay(250);
  noTone(buz);
  digitalWrite(pins[i], LOW);
  delay(250);
 } 
}