Beat 1 LED light is always on - should turn off /**************************************/
const int lowestPin = 1;//the lowest one attach to
const int speaker = 13;
int ts = 4;//how many beats you want
int count = 1;
const int keyPin = 11;
const int keyPinR = 10;
int buttonState = LOW;
int buttonState2 = LOW;
int bpm = 120;
int rthm = 1;
/**************************************/
void setup()
{
  Serial.begin(9600);
   for(int thisPin = 1;thisPin &lt;= ts;thisPin++)
   {
 pinMode(thisPin,OUTPUT); //initialize thisPin as an output
 pinMode(8, INPUT); 

 pinMode(keyPin, INPUT);
 pinMode(keyPinR, INPUT);
 digitalWrite(keyPin, HIGH);
 digitalWrite(keyPinR, HIGH); 
 }

}

/****************************************/
void loop()
{
 buttonState = digitalRead(keyPin);
 buttonState2 = digitalRead(keyPinR);
 if(buttonState==LOW){
 ts++; 
  if(ts==6)
   {
    ts = 2;
   }
  }
 if(buttonState2==LOW){
  rthm++;
    Serial.println(rthm);
  if(rthm==5)
  rthm = 1;

  }
  for(int thisPin = 1;thisPin &lt;= ts;thisPin++)
  { 

  for(int r = 1; r&lt;=rthm; r++){
   bpm = pulseIn(6, HIGH);
    digitalWrite(thisPin,HIGH);

    pinMode(13,OUTPUT); 

    if(count == 1&amp;&amp;r==1)
    tone(13,1500,40);
    else if(r==1)
    tone(13,1000,40);
    else
    tone(13,500,40);
    delay((bpm-52)/rthm);

    digitalWrite(thisPin,LOW);
    pinMode(13,INPUT);

   }
    count++;
    if(count &gt;ts)
    count = 1;
    }  

   }


This is a metronome project. Each LED represents a beat. However, The LED for beat 1 is always on. It should turn off when it's on a different beat other than one. Is there anything wrong with the code?
You are using PIN1 as an output pin and you are writing data to the Serial interface.  The serial interface uses pin 1 and 0.
Change lowestPin to 2 and ts to 5 and it will work.