user31244: this is my first project on an Arduino platform. My aim is to build up a door lock unlockable by playing a short melody on a one-octave piano keyboard. I think the idea is cool!
I'm thinking at everything, but I can't figure out how to make Arduino move something (which in my case would be the proper door lock). I thought about a little motor, but I don't know if it is or not  feasible...
To be clear, what I want to do is a simple door lock like this 
(or even simpler) being moved from an Arduino program. How can I do that?

user16085: You want a solenoid.
Looks like people sell ones which are specifically made for door locks.

31244: <p>this is my first project on an Arduino platform. My aim is to build up a door lock unlockable by playing a short melody on a one-octave piano keyboard. I think the idea is cool!
I'm thinking at everything, but I can't figure out how to make Arduino move something (which in my case would be the proper door lock). I thought about a little motor, but I don't know if it is or not  feasible...
To be clear, what I want to do is a simple door lock like this <a href="https://i.stack.imgur.com/HKaMZ.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/HKaMZ.jpg" alt="enter image description here"></a>
(or even simpler) being moved from an Arduino program. How can I do that?</p>
 16085: <p>You want a <a href="http://www.magnetschultz.co.uk/standard_and_special_solenoids/25/Miniature-solenoids" rel="nofollow noreferrer">solenoid</a>.</p>

<p>Looks like people sell <a href="https://thepihut.com/products/adafruit-lock-style-solenoid-12vdc" rel="nofollow noreferrer">ones</a> which are specifically made for door locks.</p>
