Roland GS, or just GS, sometimes expanded as General Standard or General Sound, is an extension of General MIDI specification. It requires that all GS-compatible equipment must meet a certain set of features and it documents interpretations of some MIDI commands and bytes sequences, thus defining more instrument tones, more controllers for sound effects, etc.
GS takes into account some of the criticism of simplicity of original General MIDI standard, while retaining full forward compatibility and even some backward compatibility. GS defines 98 additional tone instruments, 15 more percussion instruments, 8 more drum kits, 3 effects (reverb/chorus/variation) and some other features,thus adding more sounds to the MIDI world. Roland also gave users their own MIDI file player, called SB-55 Sound Brush.
The Roland SC-55, the first synthesizer to support the General MIDI standard, also supports the GS standard.
Organizations from around the world believed that General MIDI could be made more versatile, so Roland created the GS standard. It is still an extension of the GM specification, meaning it can provide many extra controllers and sounds while still keeping to the sound map and obeying all the protocols of GM. This means the user of the Roland GS standard will also be able to play back any song designed for General MIDI, while still giving the option to add more effects and sounds. Composers can alter sounds with the Roland GS professionally using a set of Roland exclusive system features that allow the reconfiguration and customization to be achieved. The GS extensions were first introduced and implemented on Roland Sound Canvas series modules, starting with the Roland SC-55 in 1991. The first model supported 317 instruments, 16 simultaneous melodic voices, 8 percussion voices and a compatibility mode for Roland MT-32 (although it only emulated it and lacked programmability of original MT-32) and gained explosive popularity.
The next major step in GS expansion was SC-88 that appeared in 1994. It brought counts up to 32 simultaneous voices, 654 instruments, and 24 drum sets, and occupied a position of high-end tone generator module in the market.
Currently, as software synthesizers become more and more popular, it became possible to reproduce SC-88 in software, but SC-88VL and SC-88Pro still occupy the professional musicians' niche.
In addition to the Sound Canvas series, Roland also provided GS compatibility in its own professional lineup through the JV-30 keyboard and the VE-GS1 expansion board for other JV-series instruments. In addition, GS compatibility is provided in the GM2 specification which Roland helped to create and actively supports.
The MIDI bank in the GS Standard is a recreation of the MT-32 patches. It allows additional sounds for the composer. The comparison of GS to General MIDI is still there as the program in every individual bank will align with the original 128 in GM's instrument patch map. The Sound Canvas used additional pair of controllers, cc#0 and cc#32, to specify up to 16384 (128*128) 'variations' of each melodic sound defined by General MIDI. Typically, cc#32 (Bank Select LSB) was used to select a family (i.e. 1 - SC-55, 100 - MT-32 etc.) then cc#0 (Bank Select MSB) was used to set a particular variation bank.
The drum kits were assigned their own bank, cc#0 (Bank Select MSB) 127, cc#32 (Bank Select LSB) 0, and were accessible on any channel (but could not span more than two channels), with 9 different kits in total:
- 1 Standard Kit
- 9 Room Kit
- 17 Power Kit
- 25 Electronic Kit
- 26 TR-808 Kit
- 33 Jazz Kit
- 41 Brush Kit
- 49 Orchestra Kit
- 57 Sound FX Kit
- 128 CM-64/CM-32L
The default drum kit is assigned to channel 10, with the possibility of an additional drum kit on channel 11. The extra drum kit is initialized by the SysEX string: [F0] 41 10 42 12 40 1A 15 02 0F [F7]
Additional percussion notes
There were 14 additional drum notes that span Drum Kits 1 to 49:
Additional controller events
Additional controller events included in SC-55 and SC-88 were:
- 0 Bank select MSB
- 5 Portamento time
- 32 Bank select LSB
- 65 Portamento
- 66 Sostenuto
- 67 Soft Pedal
- 84 Portamento Control
- 91 Effect 1 (Reverb) Send Level
- 93 Effect 3 (Chorus) Send Level
- 94 Effect 4 (Variation) Send Level
- 98 NRPN LSB
- 99 NRPN MSB
- 120 All Sounds Off
- 121 Reset all controllers
- 123 All notes off
There were messages that allowed the user to turn the GS mode on/off, to set effects processor parameters, to change EG envelopes etc.
Beginning in 1991, Roland introduced GS support in the majority of its MIDI products.
Tone generator modules
- DS-330 (Boss)
- Yamaha MU1000EX
- Yamaha MU2000EX