Sadly. some musical toys are not manufactured any more, like the Conn company’s song flutes, and Creative Playthings’ Xylopipes, both of which I acquired 40 years ago! The xylophone Catherine mentions above is a good idea. You could also try a small “soprano recorder” which is under eight dollars at my local music store; it comes with instructions. A small harp with standard stringing is hard to find at an affordable price, unfortunately; perhaps someone on this forum has found a source and will post it.