The acoustic drum is one of the oldest and most basic of all instruments. But modern technology has helped percussion evolve into some of the most sophisticated and diverse families of musical equipment in the modern era. You’ll find machines that can play drum parts with a precision beyond human ability, software that can mimic the performance of a live player, and pads and triggers that put thousands of sounds at the disposal of drummers and hand percussionists.
These innovations are not only available to professional performers. Thanks to computers and even musical video games, drummers are also presented with more ways to learn and practice their instrument than ever before.
But how do electronic drums work? How can a small device hold so many sounds? How are they played and programmed? And how can non-drummers use electronics percussion?
Drum machines are devices that can record and playback drum parts by triggering sounds stored in their memory. The first units were analog devices that generated electrical pulses in mixed patterns, and many of today’s hardware and software drum machines use a variation of this system – at least as a starting point.
Typically, the drum part is laid out as a grid divided by a number of steps – 16 was standard for many years. You program a pattern by first selecting a step in the pattern – step one for the first beat of the measures; step seven for the second eighth note in beat 2, etc. – and push a button associated with the drum sound to get the machine to trigger it at that step.
Today, drum machines can accommodate patterns of various lengths and subdivisions, and even add elements like swing into the pattern. They can also record performances, where the programmer plays the sounds using pads, hand triggers or a keyboard.
Samples and Pads
Early drum machines didn’t sound very realistic - though people still like the electronic noises they make. In the 1980s, Roger Linn brought realism to electronic drums through the use of short digital recordings, or samples, of real drums. Linn drum became the fashionable sound of the early 80s, and led to a whole new category of musician – people who could program beats, rather than play them.
As drum machines became more sophisticated, traditional drummers started to see a potential danger: they were losing jobs to the machines. Many became programmers. Others added electronic elements to their kits, triggering synthetic and sampled sounds with special pads.
Early drum pads were set up like drum kits, but soon compact devices with multiple pads started to appear. These offered the same basic features as full-sized electronic kits, but were small enough for one person to carry. Pads designed to be played with or without sticks let hand percussionists trigger electronics using their own set of familiar techniques.
When a drummer strikes a pad, it sends an electronic signal to a specialized computer, commonly referred to as the brain. Each pad plugs into its own input on the brain, and when it delivers a signal, the brain determines things like the strength (or velocity) and duration of the drum stroke. It uses this information to trigger sounds stored in its own memory and to send a MIDI message to a sample or computer. If each pad is assigned a different MIDI note (it’s common for the kick drum to be C3, the snare D3, etc.), the sampler will then trigger the appropriate sound.
But players can also experiment by assigning different sounds to the notes and pads, or layering sounds together. Drummers can, for example, hit a pad to trigger a whistle, orchestral hit or a horn stab. Thanks to such technology, drummers can now be more than percussionists; they, like keyboardists, have a whole orchestra of sound at their disposal.