which sensor?

Other Hardware Sensors
1

Hi

I want to make something similar to this http://www.adweek.com/creativity/agency-poster-changes-song-spotify-when-struck-flying-object-139886/

So need a sensor that will respond to bits of paper being thrown at a board/piece of card.

Advice on which sensor would be much appreciated!

2

Just use the same sensor as in the post "Piezo"

A couple of tutorials available here and here.

For the sensor itself you can get it from somewhere like here or eBay.