To get your " balloon piano" to work, you need to use the keys, Q, W, E, R, T, Y, U and I, therefore you will be able to produce the C-scale sound in order like, Do, re, Me, fa, So, La, Ti, Do. So be sure to check out this musical project out, with lots to hear and experience, as this nifty, neat, little act-out piano is great for all ages. Try press a few keys at once to see what happens..
Credits~ Scratch (tutorials)