A guitar can buzz or rattle for many reasons. A large number of repairs that come into my shop are due to complaints of buzzing or rattling when the instrument is played. When these kinds of complaints arise, I like to have the musician play for me and show me what they are hearing themselves before I attempt to examine the instrument. I do this for a few reasons. The first is that I want to eliminate one of the common causes of buzzing: poor playing technique. Any accomplished player can tell you that technique is a major influence on how your instrument will sound. A perfectly setup guitar can and will often buzz as a result of poor technique. Another reason that I have the player show me exactly what they are hearing is that often times, when a guitar comes in there is more wrong with it than the owner knows. This can include buzzes and rattles that they might not have noticed. I might hear another buzz when I sit down to do the repair that the owner of the guitar is unaware of. Also, my technique might differ from theirs, so I might not make the instrument buzz in the same way that they do when I play it. For all of these reasons, and more, I like have the owner of the instrument play me a few bars before they leave their instrument. That, and it’s nice to be serenaded from time to time!