Hi,
I have added Serial.prints to your code and edited some lines.
Open the IDE monitor with 9600baud.
The code does work just I think your LDR configuration in the circuit is back to front.
//Assign pins
int sensorPin = A0; //light sensor
int pirSENSORPin = 2; //SENSOR to detect motion, set to maximum sensitivity and range
int previousBUTTON = 4; //button on MP3 module
int playBUTTON = 3; //button on MP3 module
int legLED = 5; //leg red lights
bool PIRsensorStatus;
int ldrLevel;
void setup()
{
Serial.begin(9600);
pinMode(sensorPin, INPUT);
pinMode(pirSENSORPin, INPUT);
pinMode(previousBUTTON, OUTPUT);
pinMode(playBUTTON, OUTPUT);
pinMode(legLED, OUTPUT);
digitalWrite(previousBUTTON, HIGH); //set initial state, in my case Relay HIGH is OFF/OPEN
digitalWrite(playBUTTON, HIGH); //set initial state, in my case Relay HIGH is OFF/OPEN
digitalWrite(legLED, HIGH); //set initial state, in my case Relay HIGH is OFF/OPEN
}
void loop()
{
ldrLevel = analogRead(sensorPin);
PIRsensorStatus = digitalRead(pirSENSORPin);
Serial.print("PIR Status = ");
Serial.print(PIRsensorStatus);
Serial.print(" LDR Level = ");
Serial.println(ldrLevel);
if ((ldrLevel <= 400) && (PIRsensorStatus == HIGH)) //If its dark outside and Motion is detected
{
//Play Sound
Serial.println("Playing Sound");
digitalWrite(previousBUTTON, LOW); //PRESS previous button which plays sound from begining
delay(100);
digitalWrite(previousBUTTON, HIGH); //release previous button
delay(100);
//Leg lighting sequence
Serial.println("Start LED Sequence");
digitalWrite(legLED, LOW);
delay(8000);
digitalWrite(legLED, HIGH);
delay(100);
//Stop Sound
digitalWrite(playBUTTON, LOW); //pause/stop the sound playback
delay(100);
digitalWrite(playBUTTON, HIGH); //release play button
Serial.println("Playing Released");
// delay(500);
delay(60000); //wait 1minute before allowing to reactivate
}
}
You do not need the "else" part of the if statement if you have nothing in it.
Tom... 
