Rope-tension

Drum tuning is the process of adjusting the frequency or pitch of a drum. Although most drums are unpitched instruments, they still require tuning in order to remove unwanted overtones and produce the sound that the drummer prefers. Some drums such as timpani and rototoms are tuned to a definite pitch. Drums are tuned by tightening or loosening the tension rods or ropes, which control the tension on the drumhead. Additional techniques such as muffling may also be used.

Tuning toms is the act of ensuring that:

When tuning a drum, drummers must keep in mind that the top (batter) head controls attack and ring, while the bottom head controls resonance, sustain, overtones, and timbre.

A drum key or drum tuning key is a tool used to adjust the tension rods of a Drum. It is also used to adjust Drum hardware. It is used to adjust the pitch of a drum.

The most common pattern fits a square headed tension rod. There are minor variations of size between makers.

When tensioning a head, the tensioning rod closest to the tensioner should be tightened first. The reason for this is to keep an even tension across the drum head, which is impossible to do if the lugs are tightened differently. Next, the tension rod opposite the first lug is tightened by the same number of turns. The process is repeated for the remaining lugs in order, moving from one side of the head to the other.

When all of the rods are tightened, the first rod is once again tightened, and the process is repeated once again for each rod until the head is free of wrinkles and a very low tone is produced when hit.

The rods are further tightened in order and incrementally, by no more than a quarter turn each time. From time to time, the head is tapped next to each tension rod and the rods are tightened and loosened so that the tones are the same all around the drum.

The procedure is repeated until the head has the desired pitch. At times it may be desirable to use a specific key or individual musical notes to tune each drum to, creating more melodic tones and a more musical sound to the drums. The head is tapped once more around the edge to ensure even tuning. If double-headed drums are used, the procedure needs to be repeated with the bottom head.

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Wikipedia