Hi there, I am a high school student, and for a computer engineering project I am looking to build a circuit that can play 5 different notes or frequencies similar to those from a piano. I have looked all over the net, and to my dismay I never found a circuit I was looking for. Basically I want to build a simple circuit first that can play just one frquency, test out the different components to see how they affect the rsulting frequency (ex. if a variable capacitor changes the frquency, i will set it to the right amount to produce the correct frequency) then i will build 4 more with the correct frquencies i am looking for attach push-button switches and play it like a piano (just for reference my frequencies are 174.6Hz,185.0Hz,196.0Hz,233.1Hz, and 261.6Hz. It would be much appreciated if somone could please point me in the right direction. Thanks!!!