Build a monophonic synthesizer patch with 3 different basic oscillator waveforms to choose from. It should be possible to modulate the oscillators frequency and amplitude. Also add a filter of some kind and optionally some effects (delay, distortion etc.).
Design a graphic user interface that makes it possible to play the synth and change its parameters easily.
Maybe be of some use. It is pretty straight forward to create a basic 3 osc synth. Oscillator/Filter/Amp = Saw~/Lores~/*~ into a DAC. Connect up a few float number boxes to the various inputs on the objects and your done. Create a few oscillators like (saw~/cycle~/tri~) and use selector~ to select which one goes to the output.
Reading the manuals is best. But if you like vids check out -