Polish Or Not To Polish??.

[De Soto Frank]

One additional comment relating back to brass band instruments of the Talking Machine era...

From somewhere around the 1890's up to the Depression, most [American] band instruments were silver-plated, as this was considered easier to maintain than raw brass ( and kept hands and uniforms from turning green...).

These finishes varied - most had "satin" silver on the body of the instrument (particularly larger horns such as tubas and baritones, or complicated woodwinds such as Saxophones), while the inside of the bell was often polished, and sometimes gold-plated or gold-lacquered.

That said, I've seen plenty of 100 year-old horns that were nearly black.

The lacquering of brass band instruments probably became common once spraying technology evolved.