Can't get Coburn's code for Buzz Wire Game to compile

Using Arduino Project Guidance
33

The the handle lead is connected directly to power. So if that circuit is completed, pin 9 should be HIGH and the buzzer should sound. I just can't see where in the code pin 9's input is read and the buzzer activated.

   if (digitalRead(10) == HIGH)
   {
      delay(25);
      if (digitalRead(10) == HIGH)
      {
         while (digitalRead(10) == HIGH)
         {
            buzz(8, NOTE_B0, 1000 / 24); //[This was changed from 11 to 8]
         }
      }
   }

It looks to me like the 10 in that part of the code should be 9. Why would one read the buzzer1 output?