MML: Control Module

Accent
On / off
Volume
Sound source, eg speakers
Channel

This module should work seemlessly with SMIL 1.0 and the aural properties of CSS 2.0

1 Accent

accent: the relative loudness of beats in a bar

Music can be described in terms of rhythmic patterns of accent -- not all notes in a bar have the same loudness. So apart from pitch and time, there is also the emphasis which notes receive. This relative emphasis is declared with the accent element. Accent values are expressed as percentages compared to the loudest beat in the song, or alternatively, th eloudest beat in a phrase (in which case accent needs to be a child of phrase).

Structure:

beat number

accent value

Example

Here is an example of the long form of the accent, ie beat number are indicated.

<accent> 1:10 2:15 3:20 4:15
</accent>

It is not necessary to explicitly accentuate each beat. Only selected beats may be highlighted:

<accent> 2:15 4:15 </accent>

Non-explicit beats should then take the average accents of the whole song or phrase.

Example

Here is an example of a repeated note with different accents (in this case it is a snare intro).

<instrument type="snare">

  <bar barid="5">...</bar>
  
  <div noteset="3" note=":8">
  <bar barid="6" note=":16">(D)8 </bar>
  <accent> 65 70 75 80 85 90 95 100</accent>
  </div>
  </instrument>
  
  <instrument type="crash">
  <div noteset="3" note=":8">
  <bar barid="5">... </bar>
  <bar barid="6">(R:4)3 Fs </bar>
  </div>
  </instrument>

This is translated into English as follows

The division's default note value is 1/8 notes in octave 3.
Bar 6 consists of 8 1/16th D-notes.
The notes become progressively louder from the first (65%) to the last (100%).
On beat 8 there is a crash cymbal (note F-sharp) in the same octave.
There are 3 1/4 rests in bar 6 before the crash

This example would describe a snare intro that ends together with a crash cymbal.

2. On / off

A device or control can be switched on or off. This is done with the status attribute.

3. Volume

Volume is specified with the volume attribute.

4. Sound source

A sound source delivered through speakers or headphones can have a certain angle or origin, orientation or direction. In marketing terms this refers to 3-D or sensurround sound.

There are two methods to specify the location of the sound source with respect to the listener. Stereo systems still dominate the hi-fi (home entertainment) world, while quadraphonic systems are becoming popular in the computer environment. It is now possible to create the illusion of all around sound sources, usually by using four independent speakers.

Stereo: for a stereo effect the pan attribute is used.
For specifying the location of a sound source the azimuth attribute is used together with the elevation attribute

Examples

In this example the sound source is panned left to the value of 30.

<instrument pan="left:30">
 ...

<instrument pan="-30">
  ...

In this example the horizontal angle is right at the back, thus 180 degrees while the vertical angle of the sound source is 10 degrees.

<instrument azimuth="180deg"
elevation="10deg">
 ...

5 Channel

channel

Mixers and MIDI equipment have different channels that can be controlled. The channel attribute is used to mark the relevant channel.

<midi channel="3">
</midi>

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