I bought this as a Christmas present for my piano mat godchildren. Whether the mat is now tuned exactly I do not care, and the godchildren than ever! This is about the fun and not an early childhood music education. And have fun the children so that in any case! Of course it is annoying at some point when the kids bounce on the mat for 2 hours. From 4-year one can expect no piano sonata. But parents are also very different but familiar, right?