TromboneChat

As most of you know, a mouthpiece doughnut is a metal disk (usually brass) with a tapered hole in the middle that slides onto your mouthpiece shank to give the mouthpiece more mass. I came across this one the other day. It's polished brass, has rounded edges and has the engraving "Bass Tbone". A very nice doughnut indeed. There's only one problem; it does not fit the shank of any of my mouthpieces. The hole is too big for a small shank and too small for a large shank. It fits the best on a euro shank (Besson, Willson, etc.) euphonium mouthpiece shank (pictured below), but it doesn't go on far enough to put the mouthpiece into the instrument. Who makes it and what's it for?download/file.php?mode=view&id=40325

Looks like a shank repair tool.

https://instrumentinnovations.com/mouth ... -trombone/

Yeah the idea is that it fits over the end of the shank and you use a trueing tool inside the shank. The sleeve prevents you from over expanding the end of the shank.

The mouthpiece doughnuts that I have seen are a tool to add more mass to a lighter blank mouthpiece so that it takes on some of the qualities of a heavier blank mouthpiece. I've seen some of them fit well on one mouthpiece/horn combination and not on another (due to the mouthpiece going further into the receiver, or the shank of a different mouthpiece having a slightly different taper in the area above where it goes into the receiver). They really did work - whether it was better or worse depended on what you were looking for, sound/response -wise, but it did tighten up the slotting when you played. Chuck McAlexander of the Brasslab used to make them, among others.

Jim Scott