Video URL: http://youtube.com/watch?v=Yx5grAbKsxg
So, i found a picture sound toy at a local op-shop yesterday for $0.50. Basically, in its unaltered form it plays a four to eight bar melody for each icon / picture button on the front.
Opening it up, it was just a blob chip (as can be expected). However, there were a number of interesting bends. The first two contacts that got me interested made the circuit play the same note again and again until power is disconnected. I assume that this is something of a debug mode for the toy, or at least a test to see if the circuit is functioning and making sound.
Additionally, there were three other pairs of points that allowed for various types of distortion / rectification / cannibalism of the sound output. So these three bends combined with a standard clock resistor replacement are controlled by four pots.