A drum is not supposed to have a note. The air trapped inside the copper kettle gives this one a tune.
A drum is not supposed to have a note. The air trapped inside the copper kettle gives this one a tune.
A felt mallet strikes the head about a quarter of the way in from the rim. The centre is avoided: it excites the dull, quickly dying lowest mode, a thud with no pitch.
An ideal drumhead rings at 1, 1.59, 2.14, 2.30… times its lowest mode: a jumble, which is why most drums thump. On timpani the air above and inside the kettle loads the head and pulls its main modes to about 1 : 1.5 : 1.74 : 2 : 2.25 : 2.5. That is close to harmonics 2, 3, 4, 5 of a note that is not there, and the ear supplies it.
The kettle traps air under the head and decides how the head moves. The small hole in the bottom lets the pressure equalise.
Kettledrums came to Europe from the Middle East and the Ottoman Empire, first as cavalry instruments played on horseback in pairs with trumpets. They joined the orchestra by the middle of the 17th century. Pedal timpani, built in Dresden in the 1870s, let the player retune while playing, even in glissandi.
| Common set | 81 · 74 · 66 · 58 cm |
|---|---|
| Main modes | 1 : 1.5 : 1.74 : 2 : 2.25 : 2.5 |
| Strike | a quarter of the way in |
| Retuned by | pedal |
“The hole in the bottom of the kettle lets the sound out.”
Myth. It equalises the air pressure and affects the damping; the sound comes from the head.
