I contacted Matthias with an idea to really determine if Tako is learning music demonstrated by piano. He presses keys to lower the crab reward. So far its random.

I proposed to move the crab to specific keys. First one. Tako can only get the crab if he presses the correct key. When a second key is added, then Tako must recognise a sequence. He must press the two correct keys in sequence. How far can that sequence go? Three notes? Now he has a motif. If he can play piano in correct sequences, then not only is he learning music, maybe we can measure it. Can he learn a melody?

Might help to put a crab decal on the crab key, so he associates the decal with the crab. Two decals for the two key sequence. If flat decals don't work, maybe 3-D decals glued to the correct keys would.