| Microsoft DirectX 9.0 SDK Update (October 2004) | 
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 subelements associated with a label are shown as in the following example:
<cheh-ck> -> cheh( <DMUS_IO_CHORDENTRY> )
This notation indicates that the chunk labeled <cheh-ck> consists of the FOURCC identifier "cheh" followed by a DMUS_IO_CHORDENTRY structure.
Note The data in every chunk is preceded by a DWORD showing the size of the data. This element 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>... )