The Compensating Valve System is a system that insures that the Tuba's notes are true and correct. In order to move down a note, the path that the air is flowing in needs to either be lengthened or shortened depending on its size and which note is trying to be achieved. All Brass instruments use the Compensating Valve System except the Trombone, which evidently uses a slide to lengthen and shorten its length. Click This Link to go to an interactive activity to learn about the Compensating Valve System and how it works.
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