A proposal for compact, inspectable instrument patches built by fitting layered synthesis models to real recordings
The idea here is not just to analyze harmonics, and not just to fit attack, decay, sustain, or release curves, and not just to interpolate between a few measured notes. Those are useful tools, but they still assume that the structure of the synthesizer is mostly fixed ahead of time.
The more interesting direction is to let the system discover both the parameter values and the extra structure it needs in order to explain the sound well.