I just bought a lyre for my large bore trombone for marching band. I am having difficulties with it and was wanting to ask some questions. Its a lyre that goes to the mp shank, not the one that clamps onto the bell. I cant seem to get it to stay put. It wants to wiggle and is way to loose to use it while playing. Any help would be appreciated. Thanks.

Those lyres are just plain terrible. I've never had one actually sit in place like it should. I would suggest either purchasing the type that clips on the bell, or just memorizing the music.