07-MIDI+Common+Terms

MIDI information in such a fashion

MIDI clock is a relative timing device used to keep the performance data of audio devices that are synced together running in time. Used with a Song Position Pointer message, MIDI clocks measure songs in bars, beats and ticks (or clocks), played at a specific tempo.
 * Midi Clock**

MIDI time code (MTC) is different. Based on SMPTE time-code (a timing reference standard for video and film), MIDI time code was developed to send equivalent information between MIDI devices and to sync them together, using absolute timing. MIDI time code is sent in quarter-frame messages, as MIDI system exclusive (SysEx) data. It marks time in hours, minutes, seconds, frames and quarter frames.
 * MTC**

Developed and maintained by the MMA (MIDI Manufacturers Association), Standard MIDI Files (known as .mid files for PCs) do not contain any audio; instead they are composed of all the MIDI instructions necessary for a device to generate the specific sounds used in a sequence, track or song. This includes note arrangements, lengths, volumes, pitch settings, modulation settings and so on.
 * SMF / .Mid**

An SMF file is made up of a header chunk and one or more track chunks, and comes in one of three different formats. Format 0 files consist of a single track representing a single performance or song. Format 1 files also represent a single song, but can contain any number of its constituent tracks as originally written in a sequencer. Format 2 contains any number of tracks, each representing a separate song.

Format 0 and Format 1 SMF files can be played by many sequencers and in a variety of media players, although the use of General MIDI (GM) and Downloadable Sounds (DLS) synthesizers is required in order to enhance the accuracy of playback.

All modern sequencers should be able to save or export files as SMF’s. Along with the performance data saved, SMF files should also include a header, wherein is recorded all set-up data required to ensure that the saved songs or sequences play correctly in a different software environment. Such information could include tempo, controller settings and instrument selections for each channel, along with song titles, key signatures, credits, lyrics, copyright information and so on.


 * Binary**

While it’s not necessary to understand binary encoding to use MIDI data, a short overview may prove useful. Standard MIDI files consist of streams of binary information, which are 8 bits long. Each 8 bit section is called a byte.

In SMFs, the information is further sectioned into 4 byte chunks, each of which equates to a 32 bit binary sequence (4x8). This 32 bit binary sequence is equivalent to the decimal sequence 0-127, which is the most commonly used parameter in MIDI.

Each digit in a decimal number has a position. The position immediately to the left is called the “Units” position. Each position further to the left is 10 times bigger, while every position further to the right is 10 times smaller.
 * Decimal numbers**

The decimal system consists of 10 symbols (0-9), hence it is also known as “Base 10”. Once we have counted up to 9, we are forced to re-use these 10 symbols in a different order (10, 11, 12 etc.). However, we have other options. Binary numbers are known as “Base 2”. Using Binary, we begin counting at 0, but once we’ve reached 1, we start back at 0 again - but increase the number on the left by 1.

//Hexadecimal numbers// provide another counting alternative, using the decimal numbers 0-9 but replacing 10 to 15 with the letters A-F.


 * TABLES **

|| Decimal //Table 1 Decimal – Hex- Binary Conversion Table//
 * 0 || 1 || 2 || 3 || 4 || 5 || 6 || 7 || 8 || 9 || 10 || 11 || 12 || 13 || 14 || 15 ||
 * Hexadecimal || 0 || 1 || 2 || 3 || 4 || 5 || 6 || 7 || 8 || 9 || A || B || C || D || E || F ||
 * Binary || 0000 || 0001 || 0010 || 0011 || 0100 || 0101 || 0110 || 0111 || 1000 || 1001 || 1010 || 1011 || 1100 || 1101 || 1110 || 1111 ||