Over the centuries, much hard work has gone into devising pitch schemes, and instruments that facilitate playing those pitches. Famous tuning systems include Pythagorean, Just, Well Tempered, Equal Temperament and the Ragas of India. Many musical instruments are not designed to allow changing the tuning system during a performance. Most musicians are not trained in doing so, even on those instruments that would permit it. Most music software does not offer tuning system options to the composer. The Western standard is Equal Temperament. It is feasible to design musical instruments that allow the musician to change tuning systems during a musical phrase without a setup time. This raises another issue.
If finer and more exact pitch options become available in an instrument, the expressive practice of vibrato becomes an impediment to making these new and finer distinctions. A similar mode of expressiveness is possible in what is called tremolo (varying the loudness instead of the pitch). It is nearly impossible to perform this on current instruments, but it could be made practicable. This would need to be a capability that is as facile as vibrato. Hand control, instant by instant, would be very different from the dialed-in fixed tremolo sometimes done for electric guitars and organs, for instance.
The benefits of these changes would include the capability to perform the harmonies of a cappella choirs and barbershop quartets. There is no telling what innovations this might inspire in the field of musical composition.
There is no need to think of such innovations as the exclusive province of computers and electronic devices. Completely acoustical instruments can achieve these and many other improvements. I hope to hear from anyone who can suggest more.
Neither is it necessary to slavishly honor tradition. We can be sure that future generations will choose instruments that are easier to play and have more capability to be musically expressive.