The descriptions of DirectMusic files in the following sections use a subset of the conventional notation for RIFF files. The principal parts of this notation are shown in the following table:
| Notation | Description |
|---|---|
| <element> | File element labeled "element", or of type element |
| [ <element> ] | Optional file element |
| <element>... | One or more copies of the specified element |
| [<element>]... | Zero or more copies of the specified element |
| name, 'name', NAME, or 'NAME' | FOURCC identifier of a form type, list type, or chunk. |
| // Comment | Comment. |
Labels are used only in the notation, not in the files themselves. The label <cheh-ck> refers to a chunk with a unique FOURCC identifier and format. Wherever a chunk of this kind occurs in the notation, the same label is used.
The data or sub-elements associated with a label are described as in the following example:
<cheh-ck> -> cheh( <DMUS_IO_CHORDENTRY> )
This notation shows that the chunk labeled <cheh-ck> consists of the FOURCC identifier "cheh" followed by a DMUS_IO_CHORDENTRY structure. Of course, a DWORD showing the size of the data must precede the data as in any RIFF chunk. The presence of this data size element is assumed and is not shown in the notation.
The next example shows a list element, consisting of the FOURCC "LIST" followed by the list identifier "cmap" and one or more elements labeled <choe-list>. The <choe-list> element would be expanded elsewhere.
<cmap-list> -> LIST( 'cmap'
<choe-list>... )