There are two levels to "everything is possible." First, recorded music is a string of numbers, and any way of generating those numbers will sound like it's intended to. But synthesizing a desired sound is still an evolving process of developing useful interfaces and waveform generators.

Generating that sound in a live performance that is partially or fully improvised is a harder problem.

The evolution of solutions to either problem depends on which instrument you're interested in, and is based partially on Means, Motive, and Opportunity. There's a reason to synthesize a piano or Hammond organ, which is that they're hard to transport and maintain. Less motive for synthesizing a violin.