Random small pitch changes

Hi Experts,
I am trying to create the effect of having several violins playing a melody. To give the feel of being different performers and instruments, I make several copies a o single midi track, setting a small random variation in the position of the notes. That works fine as long as the max variation range is kept small enough.

Now I would also like to introduce very small random pitch variations in each track as if each violin was not perfectly tuned. The random pitch variations in the MIDI control work in half step intervals, which is way more out to tune than what I mean.

Any ideas on how to achieve those very small random pitch variations?

Any ideas on alternate ways to get the effect of several performers playing the melody?

Thanks in advance!