Music box

I need your guys’ help with my newest project. I’m making an electronic music box. It’s essentially https://www.instructables.com/id/Electronic-Music-Box-Powered-by-Arduino-sort-of/, but with regular LEDs instead of IR, and photoresistors instead of photodiodes. it’s an arduino hooked to 14 LEDs pointed at 14 photoresistors, with a piezo speaker hooked up. darkened areas on a piece of sheet music trigger a change in the photoresistors and play a note. I can wire up LEDs, photoresistors, and a piezo to the arduino, i just can’t figure out how to make the piezo play a certain note depending on which photoresistor changes value. Can anyone help me? Thanks.

i just can't figure out how to make the piezo play a certain note depending on which photoresistor changes value.

Use an if statement to test if your reading is above a certain threshold value, and if it does then use a different value in the tone call.