A characteristic of musical instruments is that they do not simply emit a single tone: they are multi-timbral. One way which has been used to design multi-timbral synthesizers is to characterize each note by its fundamental frequency; its attack-sustain-decay profile; and its frequency envelope (within which the harmonic overtones which characterize a certain timbre must fall.) Multi-timbral Tone Generator
Design a microprocessor-based multi-timbral tone generator. You will have to choose the number of sinusoidal signal generators to implement and include a means for varying their frequency and amplitude (there is no need to manipulate the phase because the human ear is not sensitive to phase shift.) You will also need to create an input device, possibly something akin to a piano keyboard.