How Could Anyone

The choice of sound format depends on the hardware (keyboard, MIDI player, sequencer program) you use for playback.

GM
General MIDI runs on all devices, but some have limitations in the sound range.

GM2

Number of notes - at least 32 simultaneous notes
Simultaneous percussion kits - up to 2 (channels 10/11)
Up to 16,384 variation banks are permitted, each containing a version of the 128 melodic sounds (the exact use of these banks is left to the respective manufacturer).
9 GS drum kits are included
Additional control changes have been introduced, called "Sound Controllers 1-10"

GS
The GS format is an extension of the GM format from ROLAND. It is specifically adapted for ROLAND devices.

XG
The XG format (Extended General MIDI) is an extension of the GM format from YAMAHA. Specially adapted for YAMAHA devices.

XF
XG is an extension of the GM standard and is only suitable for Yamaha devices. XF extends XG with the chord/score display.

TYROS
Special format for Yamaha Tyros devices. Compatibility with other devices is not guaranteed.

KORG PA SERIES

The adaptation of the Pro MIDIs to the new extensions is complete. All Pro MIDIs are now also available in the Korg Pa series format.

Genos

Yamaha releases its new flagship, the Genos.

Unlike in previous years, not all previous Pro or ProV MIDI files will be adapted for the Genos. Only current and popular files will be gradually converted to the keyboard-specific format.

Genos2

Yamaha launched its successor, the Genos 2, for the 2023 Christmas season. In addition to many enhancements (new user interface, new effects, massive changes to the styles), the new ambient drums and FM sound generation are worth mentioning.