Yamaha XG MIDI Format
January 18, 1996
"As the realm of interactive electronic media keeps evolving, it's time for the introduction of an enhanced format that builds upon the foundation laid by General MIDI-and that format IS XG," according to Mike D'Amore, of the Yamaha Office of Strategic Business Development. D'Amore serves as a liaison between Yamaha's engineering and marketing departments and United States-based software and hardware developers.
For more than a decade, MIDI (the Musical Instrument Digital Interface) has provided musicians with a powerful set of tools, forever changing the way people create and listen to music. MIDI has proven to be a durable standard and has undergone relatively few refinements through the years. But the original specification provided few exact guidelines as to how these tools should be used.
In January 1995, Yamaha introduced an enhanced format called XG that builds on the foundation laid by General MIDI, but is designed for the latest generation of multimedia audio products.
Forward-thinking and with dozens of advanced features, XG has already garnered overwhelmingly enthusiastic response from the international community of musicians, game developers, and producers of multimedia content. Yamaha's development of the XG format has focused on three key goals: Compatibility, Scalability and Expandability.
Compatibility - Any XG instrument, regardless of model or manufacturer, will not only provide faithful reproduction of XG music files but will also be completely 100-percent General MIDI-compatible, since XG is an enhancement to, and not a replacement for, General MIDI.
Scalability - There are actually different levels of XG compatibility, as implemented in mid-range instruments such as the Yamaha MU50 tone generator and WaveForce DB50XG daughterboard, or in high-end instruments such as the Yamaha MU80 tone generator. This makes for a wide range of XG instruments, each with its own character and each offering a unique feature set at a different price point.
Expandability - The XG format-like MIDI itself-is an "open" architecture, which will allow for the addition of new enhancements as future technology continues to evolve as long as it does not affect the compatibility or scalability.
The XG format expands on the General MIDI standard in the following major areas including the number of voices:
- Support - GM supports 128 voices, the XG format enables access to
literally thousands of voices.
- Voice organization - GM stipulates the use of a total of 128 sounds, organized
into 16 groupings of 8 each. XG takes many steps further by specifying the use of
more than a hundred "Banks," each of which contains 128 sounds.
- Polyphony - XG instruments are required to play at least 32 notes simultaneously, while GM instruments are only required to play 24 notes.
- Additional Rhythm Channels - Following the GM convention, XG instruments normally use MIDI channel 10 for rhythm sounds. However, the XG format allows additional channels to be designated for rhythm parts as well.
- Support for Internal Effects - The XG format provides support for a minimum of three different effects (Reverb, Chorus, and a switchable global or "insertion" effect) as well as for a fourth internal "insertion" effect and an optional internal master graphic equalizer.
- Optional Support for External Audio (A/D) Input - The XG format allows the musician to become a live participant by providing optional support for external audio input, i.e. microphones, electric guitars, etc.
- Voice Modification - GM specifies the use of only a handful of control sources for the realtime modification of voices. XG supplements these with more than a dozen additional control change messages, including piano-like Sostenuto pedal and Soft pedal.
- XG Music Data - The introduction of GM in 1991 quickly led to the proliferation of commercially available GM music data-standard MIDI files on disk, optimized for playback on GM instruments. Similarly, a wide range of XG music data will soon be available as well. "Dozens of third party manufacturers are currently creating commercial XG music files that take advantage of these new features, enabling XG instruments to play back full-blown music productions," explains D'Amore. "What we see in XG greatly surpasses what is considered 'state of the art' in MIDI, and clearly has the potential to become the standard of the future."
For more information, visit their web site at www.yamaha.com. |
