In large Tegu sets, in addition to cubes and thin planks, there are also bricks with 6 magnets in them. At the end of a brick there is also a magnet. The bricks were placed between the cubes like the keys in a piano. If you press them, the bricks spring back, almost like in a real piano, only there is no sound, but children voiced it themselves. It turned out a funny piano with one incomplete octave. Invented by Anny (7 years old).
