Comment on how to get more arduino analog inputs by Caesar P

I have a question . With the multiplexed code above can I read any and all of the eight inputs. Let stay I have piezo sensors (8 on each multiplexer) would the code bet able to accept input from any of the piezos i hit. Or do I have manually select the pin I want to read? I see the code has some can of loop function is this scan all the pins and ready to read and of the inputs active? I and new to the arduino world and appreciate any advice you can offer.
Thank you in advance