What is THIS?

This strange box plays music and then a MONKEY pops up. I had to look at it from a distance at first. I don't trust it one bit.

Hmmm...I saw Mommy turning this knob. I'm not so sure about this.

Oh that was fun! Do again Mommy, do again!

P.S. Daddy spent all last weekend sanding and restaining our deck. Doesn't it look good? It's so much fun to play on now.