Bruce Clark asks about polishing brass.  I have been polishing brass
for many years for various reasons and have come to the conclusion that
the only way to keep metals polished is to buff them with a succession
of finer and finer abrasives until they are "perfect." They will stay
shiny for a very long time.

Most polishes remove tarnish by a mildly corrosive action which leaves a
rough and porous surface which tarnishes again very rapidly.  Buffing
with grease or wax based abrasives (the normal stick polishes such as
Tripoli and rouge) smoothes the metal and leaves a light wax or grease
coating to protest the surface.

Unfortunately this is not something that can be done to do on a tracker
bar that is in the piano, but once it is done, the roll paper should
keep the bar bright indefinitely.

Spencer Chase