How do I quiet a squeaky brass door hinge?
Just lubricate the hinge with a few drops of oil. I use a 3-in-1 household type oil. Hold a tissue at the bottom of the hinge pin while you put a few drops of oil at the first hinge joint, or at the top of the first pin/hinge connection. The oil will be sucked into the hinge by capillary action, and any excess oil will be caught by the tissue.
Repeat this for all hinges. While you’re at it, do it to all the doors in your home. Repeat this every year or two.