stylistic:style_transfer, quality:correction
Trigger or throw

Some valved brass instruments provide triggers or throws that manually lengthen (or, less commonly, shorten) the main tuning slide, a valve slide, or the main tubing. These mechanisms alter the pitch of notes that are naturally sharp in a specific register of the instrument, or shift the instrument to another playing range. Triggers and throws permit speedy adjustment while playing.

Trigger is used in two senses:

A throw is a simple metal grip for the player's finger or thumb, attached to a valve slide. The general term "throw" can describe a u-hook, a saddle (u-shaped grips), or a ring (ring-shape grip) in which a player's finger or thumb rests. A player extends a finger or thumb to lengthen a slide, and retracts the finger to return the slide to its original position.