How do you fix a really loose trumpet key on a bach 701 trumpet?
Here is a better reply: Just screwing the key back on may not help. Trumpets are instruments with highly movable parts. The mounts that hold the keys are either pure brass (for the better quality trumpets) or brass plated steel alloy (for the less expensive trumpets). Brass is fairly soft as metals go and wears out when exposed to friction over a period of time. The threads of the screw, or in the screw channel, holding the key in place may be so worn that even trying to tighten the screw won’t work any more. If this is the case you’ve really only got two options: Either re-thread the screw channel (which will require a tap-and-die tool) and use a new and unworn screw or find and use a slightly larger screw that will bore itself into the screw channel and hold tight. Unless you’re mechanically inclined you would be better off taking your beloved trumpet to a music store that sells and repairs instruments. And while you’re there have them check out and look for wear on the rest of the k
