[mikamika] has put together a great tutorial on how to build this musical shirt. The whole process is covered, from taking apart the toy keyboard to laying out the circuit and creating the fabric switches.  He used the same method as [plusea] for the fabric buttons and conductive thread for a lot of of the connections. It seems as though he has actually taken [plusea]’s wearable tee shirt project and added some polish. His looks good enough, he might even be able to make it through an airport.