Arduino VU Meter

#define NUMREADINGS 5 // Number of readings (increase for a slow curve)
#define MINSOUND 25   // Min sound intensity
#define MAXSOUND 125  // Max sound intensity

const int firstLED = 2;
const int lastLED = 9;
int leds;
int readings[NUMREADINGS];
int index = 0;
int total = 0;
int average = 0;
int sound = 0;

int x = 0;
int y = 0;

void setup() {
    for (int r = 0; r < NUMREADINGS; r++) {
        readings[r] = 0;
    }
    for (int p = firstLED; p <= lastLED; p++) {
        pinMode(p, OUTPUT);
    }
    leds = (lastLED - firstLED) + 1;
}

void loop() {
    total -= readings[index];
    readings[index] = analogRead(0);
    total += readings[index];
    index++;

    if (index >= NUMREADINGS) {
       index = 0;
    }

    average = abs((total / NUMREADINGS) - 338); // ((1024 * 300) / 1000) = ~338
    sound = map(average, MINSOUND, MAXSOUND, 0, leds);

    for (int ledON = firstLED; ledON < (firstLED + sound); ledON++) {
        digitalWrite(ledON, HIGH);
    }

    for (int ledOFF = (firstLED + sound); ledOFF <= lastLED; ledOFF++) {
        digitalWrite(ledOFF, LOW);
    }

    digitalWrite(10, HIGH);
    digitalWrite(11, HIGH);
}