oh nooooooooooooo, i can't believe it!!! It is actually WORKING!!! 
There are two piezos not working and one that plays two notes at the same time. But i'll take a look at this tomorrow when there is more light and i have some more energy (probably i have some connections in the breadboard that opened from all the moving around)!
THANK YOU SOOOO MUCH! I think this has been a great step towards making this project come true!
=)
Stay tuned for the next chapter...
