Hi,
first of all i want to tell you that in toys like the one in attached image use simple melody generator ic. A lot of models of such ic,s are avialable in different packages ranging from simple 3-pin TO-92. to large DIP as well as SMD versions. some are high quality melody generators,others are not. some are multi melody with options of selections, others may be just one or couple of melodies.
now in the image you posted , there is not visible any DIP or SMD ic on circuit board. I can see just TO-92 models. you need to look at those transistors and post there markings.
i think one of them is not a transistor, but it may be be a melody generator. post there marking and may be i could help you.
You may need to see the other side of the board for any smd IC or a blob of white or black epoxy on the board(worst case it will be).