Since it became available, I've always used Scotch Magic Mending
Tape, and I use it on the side of the roll away from the tracker bar.
I first learned of Scotch Magic Mending Tape from a book restorer who
did work for several libraries, so I figured that if it was good enough
to use on valuable books it should be okay for music rolls, too.

Then, to reduce any chance of the adhesive from the tape reaching
through any opening in the roll, I use a liberal application of talcum
powder and gently rub it over all the possible places where adhesive
from the tape might reach through.  Following this it's a simple matter
to brush off the excess powder.

This has worked fine for me for many years.

Hal Davis