![]() ![]() GM also specifies which operations should be performed by multiple Control Numbers. In MIDI, adjustable parameters for each of the 16 possible MIDI channels may be set with the Control Change (CC) message, which has a Control Number parameter and a Control Value parameter (expressed in a range from 0 to 127). If a MIDI file is programmed to the General MIDI protocol, then the results are predictable, but timbre and sound fidelity may vary depending on the quality of the GM synthesizer: Each of the 128 different possible note numbers correlate to a unique percussive instrument, but the sound's pitch is not relative to the note number. Notes recorded on channel 10 always produce percussion sounds when transmitted to a keyboard or synth module which uses the GM standard. In GM standard MIDI files, channel 10 is reserved for percussion instruments only. ![]() The 0 to 127 numbering is usually only used internally by the synthesizer the vast majority of MIDI devices, digital audio workstations and professional MIDI sequencers display these Program Numbers as shown in the table (1–128). The numbers can be displayed as values 1 to 128, or, alternatively, as 0 to 127. The following table shows which instrument sound corresponds to each of the 128 possible Program Numbers for GM only. In MIDI, the instrument sound or "program" for each of the 16 possible MIDI channels is selected with the Program Change message, which has a Program Number parameter. GM Instruments must also obey the following conventions for program and controller events: Program change events Respond to the data entry controller and the RPNs for fine and coarse tuning and pitch bend range, as well as all General MIDI Level 1 System Messages. Support for controller number 1, 7, 10, 11, 64, 100, 101, 121 and 123 support for channel pressure and pitch bend controllers. Support a minimum of 128 MIDI Program Numbers (conforming to the GM 1 Instrument Patch Map) and 47 percussion sounds (conforming to the GM 1 Percussion Key Map). Support polyphony (multiple simultaneous notes) on each channel. Support all 16 channels simultaneously, each assignable to different instruments. To be GM 1 compatible, sound generating devices (keyboards, hardware or software synthesizers, sound cards) are required to meet the General MIDI System Level 1 performance specification: CriterionĪllow 24 voices to be available simultaneously for both melodic and percussive sounds (alternatively, allow 16 melodic and 8 percussive voices). General MIDI was widely supported by computer game developers in the 1990s. The GM 1 specification was superseded by General MIDI 2 in 1999 however, GM 1 is still commonly used. Instrument selection in MIDI is done by assigning a "Program Number": this assignment previously was arbitrary, while a specific instrument is attributed to each program number with GM. GM ensures that playback of MIDI files sounds consistently between different devices compliant with the GM specification. While MIDI 1.0 by itself provides a communications protocol which ensures that different instruments can interoperate at a fundamental level (e.g., that pressing keys on a MIDI keyboard will cause an attached MIDI sound module to play musical notes), GM goes further in two ways: it requires that all GM-compatible instruments meet a certain minimal set of features, such as being able to play at least 24 notes simultaneously ( polyphony), and it attaches specific interpretations to many parameters and control messages which were left unspecified in the MIDI 1.0 spec, such as defining instrument sounds for each of the 128 possible program numbers. GM imposes several requirements beyond the more abstract MIDI 1.0 specification. The official specification is available in English from the MMA, bound together with the MIDI 1.0 specification, and in Japanese from the Association of Musical Electronic Industry (AMEI). GM was developed by the American MIDI Manufacturers Association (MMA) and the Japan MIDI Standards Committee (JMSC) and first published in 1991. General MIDI (also known as GM or GM 1) is a standardized specification for electronic musical instruments that respond to MIDI messages. ![]()
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |