For centuries, drums have been an integral part of music, used in everything from tribal music through jazz, rock and blues, right through to symphony orchestras. In many cultures, drums play an integral part during ceremonies and religious events.

Modern drums tend to be based on instruments that are used in established cultures. For example, from the Afro-Cuban cultures we have been introduced to the bongo and the congas while from the American native Indians comes the tom tom. Cymbals of various descriptions have originated from Europe, Turkey and China.

Traditionally, drums have tended to be made from natural products such as carved timber and animal skins while cymbals are usually manufactured from brass. These instruments have a charm of their own and produce a unique sound that is dependent on the products used in their manufacture.

Modern instruments are made using high-technology materials such as stainless steel, aluminium and its alloys, plus many types of plastics. The sound produced by these instruments can be tightly controlled so that each instrument has a distinctive and consistent sound.

Often, these sounds are recorded in a digital form so that they can be played back using a synthesiser. The technique for recording is called sampling.

Other synthesiser sounds are not recordings at all but synthesised sounds made using oscillators, noise and envelope control to recreate the required effect.

Once the drum sounds are recorded or created, we can replay them repeatedly just by signalling the synthesiser to play a particular sample.

The data sent to the synthesiser is in a format called MIDI (Musical Instrument Digital Interface) and includes information such as the required instrument to be played, its volume and its position in the left and right sound stage.

By adding sensors to detect when the recorded "drum" sound is to be played, we can drive the synthesiser with the MIDI signal to faithfully reproduce the required drum sound whenever the sensor is struck. (For a more detailed description of MIDI and the way it works, refer to the "MIDI Theremin" articles in SILICON CHIP, April/May 2005).

This is the basis of an electronic drum kit – and the project presented here, the SILICON CHIP MIDI Drum Kit. It can reproduce a vast array of drum sounds without having to use conventional instruments to make the sounds.

Drum sounds can be initiated using an electronic keyboard to play the instruments or you can use a drum kit. The advantage of the drum kit is that it can be played in a similar way to a real drum set, so its operation is more natural.

Features Sound output via a computer and speakers or synthesiser Up to 21 instruments selectable for the standard drum kit set 7 extra kits (with MIDI 2) including Brush, Jazz and Orchestra sets 7 instruments can be played at the one time Footswitch control of instrument No.7 to select another instrument (eg, closed and open Top Hat) Instrument triggers include percussion plate, hand plate and footxxi activation units Volume level can vary with striking pressure on the trigger plate x Four settings for sensor pad volume: wide variation, two compressed and a fixed full level LCD shows sensor selections, patch and volume level and settings Adjustable soundstage positioning within left and right channels Can be used with a synthesiser or computer (with sound card) MIDI out, sound card (DB15) or serial (DB9) connections USB operation via a serial to USB converter Plugpack powered