Adding a Line Output to a Green Toy Keyboard

I have a small, green toy keyboard that uses a series of small granular balls that sit enclosed on top of the built in speaker to add a little noisy effect and percussion to the sound as the keyboard it played. I like this design, but I wanted to see what it sounds like with a direct line output - bypassing this speaker setup - so I replaced the speaker with a line output. You can hear what the keyboard sounded like previously because I made a sample pack out of it.