A HISTORY OF KEYBOARDS - various types
Música e Tecnologia nº 45 (May-June 1994, p.70-73) & nº 46 (July-August 1994, p.64-68)

The first synthesizers
Mini Moog Model D (Moog), ARP 2600 (ARP), Mini Korg (Korg), etc. During the late 1960s, experiments were under way with modular synthesizers that used voltage-controlled circuits developed by Moog, ARP and Bulcla. In 1970 the first small analog monophonic synthesizers were launched, producing sound through electronic circuits and oscillators using transistors.

Polyphonic Analog Synthesizers with incorporated microprocessors
Memory Moog (Moog), Prophet V (Sequencial Circuits), etc. During the early 1980s, microprocessor-controlled polyphonic analog synthesizers were launched. These instruments used chip technology allowing complex operations to be memorized, whilst also reducing the weight and size of the device.

Analog/Digital Synthesizers
ROLAND JX8P e JD800, OBXA, Matrix 6, Matrix 1000 (Oberheim), etc. Instruments generating sounds from analog circuits which are then processed digitally, and can be edited and filed in various internal memory banks, on tape cassettes, hard disks or other devices.

FM Synthesizers
DX 7, DX 7 II, DX 21, FB01, TX 81Z, V50 (Yamaha), etc. From 1990 onwards, Yamaha introduced FM instruments to the market, in a more sophisticated version called Advanced FM (AFM). Instruments such as the SY 22, SY 55, SY 77 and SY 99 are based on this technology, while also mixing sound samples at 16 bits in ROM. FM type sound is basically generated by producing a digital senoidal wave that modulates another wave with the same characteristics as the first. The modulating device is called the modulator, whilst the modulated wave is called the carrier.

LA Synthesizers (linear arithmetic)
D 20, D 50, D 550, D 70 e MT 32 (Roland), etc. This is a type of subtractive synthesis that uses up to four elements to produce a sound. This type of technology was introduced by Roland, with the D50 keyboard. This instrument combines takes of approximately 200 milliseconds of 100 previously-sampled sounds (PCM in ROM), with sounds synthesized from the same type of oscillator as the JX8P.

VS Synthesizers (vector synthesis)
Prophet VS (Sequencial Circuits), Wavestation (Korg), etc. The VS technology was developed in order to allow greater interaction between the wave forms available on an instrument. It is based on recording sequencing through a joystick, moving from one wave form to another, and thus varying the sound produced by a patch. The sound produced by instruments that use VS technology can be compared to an avalanche of timbres.

Samplers
S-50, S-330, S-550, W-30, S-770 (Roland), E-mu Emax HD, E-mu Emax II (Emulator), EPS (Ensoniq), S 2000 (Akai), TX 16W (Yamaha), Dynacord ADS (Dynacord), etc. Instruments, racks or modules that digitally record any sound data applicable at the record input port. The Audio-Frequency Bandwidth of the digitally sampled sounds is determined by the sample rate, meaning the number of times per second that the sound is sampled.

Keyboards and multitimbral modular instruments
Proteus 1XR, Proteus II (E-mu), M1, M1R, M3R (Korg), MT 32, MT 100, MV 30, D70, (Roland), K4 (Kawai), TG 77 e SY 77 (Yamaha), etc. These are instruments or modules that receive on various MIDI channels simultaneously, addressing each sound to a separate audio output or the stereo output. The number of voices available is distributed according to the number of notes played on a MIDI channel. At the moment, almost all keyboard instruments, modules and sound boards are multitimbral.

Interfaces with internal sound - multimedia
RAP-10, SC-7, SCC-1 GS (Roland), Sound Blaster Live (Creative Labs), etc. Installed in a desktop computer slot, they offer great versatility, as instrument sounds are built in. This makes it possible to create a multimedia presentation with no need to link in keyboards or external modules. Interfaces using LA, FM and Sampler technology are available on the market. This latter acts as a sample player, meaning it plays sounds previously sampled at 44.1 or 48 kHz at 16 bits. In terms of fidelity this is the only method that can be really recommended for obtaining good results directly on the computer.

OTHER ARTICLES (portuguese only)

Ébano, marfim e microchips: piano computadorizado Bösendorfer 275 SE
Informática & Etc, O Globo, 20 de maio de 1991, p.16

Análise do módulo multitimbral MU (Yamaha)
Revista Música & Tecnologia, agosto de 1995

Análise do sistema de gravação de áudio / sequenciamento / notação musical Cakewalk Pro Audio CD DL
Revista Música & Tecnologia, nº 58, 1996

Análise do programa de notação musical Finale 3.7 (Coda Music Technology)
Revista Música & Tecnologia, nº 58, fevereiro de 1997.

Análise do programa de notação musical Finale 97 (Coda Music Technology)
Revista Música & Tecnologia, nº 58, abril de 1998.

Análise do sitema de gravação de áudio / sequenciamento / notação musical Audiowerk8 Home Studio Kit (Emagic)
Revista Música & Tecnologia, agosto de 1998.