Goal -
Build a drummer person that has one input (move head) and two different out puts (one arm moves up and the other down).

In science and engineering, a black box is a object which can be viewed solely in terms of its input, output and transfer characteristics without any knowledge of its internal workings. The opposite of a black box is a system where the inner components are available for inspection.
Reverse engineering is the process of discovering the technological principles of a device, object, or system through analysis of its structure, function, and operation. It often involves taking something apart and analyzing its workings in detail to be used in maintenance, or to
try to make a new device that does the same thing without using or simply duplicating the original.

More ideas

3 Gears - detailed instructions
LEGO Links of Linda Hamilton
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