Hello, let me introduce us, we are a group of software and hardware developers, call Knowledge, we have worked with arduino for a long time by now, you can see our portfolio and see some of our many projects with arduino. What you are asking for sound pretty easy for us but for what we can see you are missing some variables, like where you want the music to be playing, are you asking just for the code and hardware or for the design of the toy too.
We believe that we are what you need for this project. if you are interested on working with us let us know we will be really happy to be able to help you with your project.
P.D we know that we don't have any review but we just stater to work with Freelancer, and this will we be our second project. so don worry about that.
Thanks and have a nice day.