MPR121 Capacitive Touch Sensor Synth

The problem is, the tutorial says that you can use the sensors to trigger specific events (like sound) with the following addition to the code

Where did you put that extra code?

and I cant get it to compile...

It's pretty simple really. Click Verify. Fix any errors. Repeat until there are no errors.

Since you didn't post any errors, I'll have to assume that there were none, so I can't imagine what your problem is.