For all the people interested in technical stuff...
Here is some information about my Yamaha MU80 tone generator. Also I've
listed the differences between General MIDI and XG standard.


FEATURES:

 * 729 high-quality voices
 * Full General MIDI compatibility
 * Host computer interface and MIDI terminals
 * Large LCD and intuitive graphic controls, easy to use
 * Independent dual MIDI inputs, 32 Part multi-timbral
 * 64-note polyphony
 * Special Performance mode
 * Built-in digital multi-effects
   (each one for reverb, chorus, variation, distortion and equalizer)
 * Mixable A/D input (two channels)


  YAMAHA  [ Tone Generator ]                           Date:28-OCT-1994
          Model  MU80 MIDI Implementation Chart        Version : 1.0
+----------------------------------------------------------------------+
|                   |  Transmitted   |   Recognized   |    Remarks     |
|      Function ... |                |                |                |
|-------------------+----------------+----------------+----------------|
|Basic    Default   | x              | 1 - 16         | memorized      |
|Channel  Changed   | x              | 1 - 16         |                |
|-------------------+----------------+----------------+----------------|
|         Default   | x              | 3              |                |
|Mode     Messages  | x              | 3,4(m = 1)  *2 |                |
|         Altered   | ************** | x              |                |
|-------------------+----------------+----------------+----------------|
|Note               | x              | 0 - 127        |                |
|Number : True voice| ************** | 0 - 127        |                |
|-------------------+----------------+----------------+----------------|
|Velocity Note ON   | x              | o  9nH,v=1-127 |                |
|         Note OFF  | x              | x              |                |
|-------------------+----------------+----------------+----------------|
|After    Key's     | x              | o           *1 |                |
|Touch    Ch's      | x              | o           *1 |                |
|-------------------+----------------+----------------+----------------|
|Pitch Bender       | x              | o 0-24 semi *1 |                |
|-------------------+----------------+----------------+----------------|
|              0,32 | x              | o           *1 |Bank Select     |
|       1,5,7,10,11 | x              | o           *1 |                |
|              6,38 | x              | o              |Data Entry      |
|             64-67 | x              | o           *1 |                |
| Control     71-74 | x              | o              |Sound Controller|
|                84 | x              | o              |Portamento Cntrl|
| Change   91,93,94 | x              | o              |Effect Depth    |
|             96,97 | x              | o              |Data Entry SW   |
|             98-99 | x              | o           *1 |NRPN LSB,MSB    |
|           100-101 | x              | o           *1 |RPN LSB,MSB     |
|               120 | x              | o              |All Sound Off   |
|               121 | x              | o              |Reset All Cntrls|
|-------------------+----------------+----------------+----------------|
|Prog               | x              | o  0 - 127     |                |
|Change : True #    | ************** |                |                |
|-------------------+----------------+----------------+----------------|
|System Exclusive   | o           *3 | o           *3 |                |
|-------------------+----------------+----------------+----------------|
|System : Song Pos. | x              | x              |                |
|       : Song Sel. | x              | x              |                |
|Common : Tune      | x              | x              |                |
|-------------------+----------------+----------------+----------------|
|System    :Clock   | x              | x              |                |
|Real Time :Commands| x              | x              |                |
|-------------------+----------------+----------------+----------------|
|Aux  :Local ON/OFF | x              | x              |                |
|     :All Notes OFF| x              | o(123-127)     |                |
|Mes- :Active Sense | x              | o              |                |
|sages:Reset        | x              | x              |                |
|-------------------+----------------+----------------+----------------|
|Notes: *1  ; receive if switch is on.                                 |
|       *2  ; m is always treated as "1" regardless of its value.      |
|       *3  ; transmit/receive if exclusive switch is on.              |
|                                                                      |
|                                                                      |
+----------------------------------------------------------------------+
  Mode 1: OMNI ON,  POLY    Mode 2: OMNI ON,  MONO            o:  Yes
  Mode 3: OMNI OFF, POLY    Mode 4: OMNI OFF, MONO            x:  No


+----------------------------------------------------------------------+
|                 | General MIDI (GM)      | Extended General MIDI (XG)|
|                 |                        |                           |
+-----------------+------------------------+---------------------------+
|Polyphony        | 24-note                | 64-note                   |
+-----------------+------------------------+---------------------------+
|Multi-timbral    | 16-part capacity       | 32-part capacity          |
+----------------------------------------------------------------------+
|Voices           | 128                    | 729                       |
+----------------------------------------------------------------------+
|                 |                        | Several effects and       |
|                 |                        | controllers in realtime   |
+----------------------------------------------------------------------+


IMPORTANT: All information according to my MU80 manual. I can't guarantee
           that these specifications are absolutly correct (even if I think
           they are).