old door bell

I've removed a door bell that played songs and installed a new chime bell.There was a slight short on the line and I found a capactor or resistor wired to the front door button.So I remover it all worked .Now the people want the old door bell installed at their new home.quess what ? it won't play the entire song.If you hold the button down it will keep playing the entire song ,but who does that,I need to know what I removed from the front door button to make it play the entire song,any answers?