Author Topic: what is the difference between XG GS GM AND GM2?  (Read 2740 times)

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Offline anon125

what is the difference between XG GS GM AND GM2?
« on: January 10, 2020, 08:54:26 PM »
Omigod expensive psrxs900 has all of them

Thanks every one

Offline Gunnar Jonny

Re: what is the difference between XG GS GM AND GM2?
« Reply #1 on: January 10, 2020, 09:48:25 PM »
Hi :)
Here is some info that may be helpful to clarify the differences:
Cheers 🥂
"Success is not counted by how high you have climbed
but by how many you brought with you." (Wil Rose)

Offline anon125

Re: what is the difference between XG GS GM AND GM2?
« Reply #2 on: January 10, 2020, 10:20:57 PM »
Who knew it could be so complicated!
We just need a nice sounding  keyboard without  having to use headphones!


Offline SeaGtGruff

Re: what is the difference between XG GS GM AND GM2?
« Reply #3 on: January 11, 2020, 03:59:01 AM »
GM came first.

Initially, there weren't very many tones on a keyboard; you might be lucky to buy a keyboard with 5 tones, then 10, then 20, etc. Even today, you can still see a lot of old Casios and Yamahas for sale on Craigslist and eBay that boast the incredibly mind-boggling number of-- wait for it-- 100 different tones!

Once it was possible to put 100 different tones on a keyboard, with a wide variety of instrument sounds such as piano, organ, accordion, guitar, flute, violin, trumpet, saxophone, etc., musicians could begin to seriously think about making and sharing MIDI song files for a wide variety of music-- pop, rock, rhythm and blues, country and western, big band, symphonic, etc.

But there was no consistency between manufacturers as far as which Program Number selected which tone, and that was a real problem, because a MIDI file for a particular song might sound as expected if played back on a given model of keyboard, yet sound totally unexpected if played back on another model-- e.g., the piano part might sound like a xylophone, the guitar part might sound like a tuba, the bass part might sound like a flute, etc.

So the MMA (MIDI Manufacturers Association) convened and came up with a standard correlation between Program Numbers and the tones they select. Due to the way MIDI messages are constructed as far as their bits and bytes, a data byte could have 128 different values, so when the MMA created the GM standard they specified a list of 128 different instrument sounds. Remember, this was at a time when having 100 different tones on a keyboard was an impressive feat, so a standard that identified 128 different tones must have seemed like it was covering all the bases.

Also, due to the way the percussion tones or drum kit worked-- a different sound for each key, as opposed to the keys playing different pitches of the same sound-- the correlation between keys and percussion sounds needed to be standardized, too. There wasn't yet a need for more than a single drum kit, so rather than assign one of the 128 Program Numbers to the standard drum kit, it was decided to dedicate MIDI channel 10 to the drum kit and let all 128 of the Program Numbers be used for melodic tones.

But technology always advances faster than expected, and soon 128 melodic tones and a single drum kit just weren't enough to contain all the different instrument sounds and types of drum sounds that manufacturers could produce and that musicians wanted to create with. So the different manufacturers began looking into ways to extend the GM standard. In particular, Yamaha created an extension of GM that they called XG, and Roland created an extension of their own that they called GS. Both of these extensions to GM added the ability to have many different tone banks-- potentially as many as 16,384 (or 128 times 128)-- with each tone bank potentially having 128 different tones in it.

In actual practice, many of the extra tone banks contain only a handful of tones in them, and different manufacturers have established their own protocols for which tone bank numbers they use and whether they put more emphasis on the Bank Select MSB or the Bank Select LSB. For instance, for their XG tones Yamaha used MSB 0 and used different LSB values for their different tone banks, whereas Casio generally used LSB 0 and then used different MSB values for their different tone banks.

By the way, another thing tone banks did was allow for more than a single drum kit, since drum kits could have their own bank numbers, with up to 128 drum kits (or Program Numbers) in each bank. This had the secondary benefit of freeing channel 10 from being exclusively used for drums, since it was now possible to assign drum kits to any of the channels-- even to multiple channels at once-- and to assign a melodic tone to channel 10 if desired.

Since it looked like the situation was starting to get out of control again, and it was obvious that the 128 GM tones and single standard drum kit weren't adequate for meeting musicians' wants and needs, the MMA agreed on a new version of GM called GM2. It standardized many of the Control Change numbers that Yamaha and Roland were using in their XG and GS extensions of GM. This didn't stop Yamaha, Roland, and other companies from continuing to do their own things, but it did at least establish what the different Control Change numbers mean and how the different Control Change messages are to be used as far as their data bytes. And GM2 also defined some additional instrument sounds and drum kits.

So basically, GM, XG, GS, and GM2 are all about trying to establish standards and standardized sets of sounds (tones, voices, programs, or whatever each manufacturer likes to call them) so MIDI files can be created by companies and sold to musicians, or created by musicians and shared with other musicians, and played back by different hardware or software with some assurance that the results will be as expected. When a manufacturer advertises that a particular model of keyboard is GM compatible, or XG compatible, or GS compatible, or GM2 compatible, they're letting people know which types of MIDI files can be played back on that keyboard. It's largely a matter of the program sounds, but it's also a matter of which MIDI messages-- especially which CC messages and which Universal SysEx messages-- the keyboard can recognize and respond to.

Obviously, for the greatest flexibility and degree of compatibility, it's best to have a keyboard that can reliably play back MIDI files which adhere to the GM, XG, GS, and GM2 standards.
« Last Edit: January 11, 2020, 04:06:19 AM by SeaGtGruff »
Michael Rideout
Current keyboards: Yamaha YPT-400, PSR-E433, PSR-E443, PSR-EW400, MX49 BK
Current controllers: M-Audio Axiom 61-II
Previous keyboards: Farfisa Matador 611; Casio CTK-710
The following users thanked this post: terryB, Dick Rector, pjd, Mjm, Jay B., Milamber, AndyMark

Offline tyrosrick

Re: what is the difference between XG GS GM AND GM2?
« Reply #4 on: January 13, 2020, 10:56:36 AM »
 :-*Now THAT was one helluva in-depth explanation. Thank you so much as I'm sure many others here learned a great deal from it.

Offline Mjm

Re: what is the difference between XG GS GM AND GM2?
« Reply #5 on: January 13, 2020, 06:14:38 PM »
Thank you Michael, for taking the time to explain so clearly, the difference/reason for the different types of voices. It makes much more sense to me now. 🙂


Offline DrakeM

Re: what is the difference between XG GS GM AND GM2?
« Reply #6 on: January 17, 2020, 12:48:55 PM »
When creating your own riffs and licks, I find you can sometimes get a BETTER finished sound using one of the GM voices and THEN switch it to the move advanced Voices, like a SWEET, COOL or LIVE Yamaha voice.