The IDirectMusicComposer interface permits access to the composition engine. In addition to building new segments from templates and chordmaps, the composer can generate transitions between different segments. It can also apply a chordmap to an existing segment, thus altering the chord progression and the mood of the music.
For an overview, see Music Composition.
The methods of the IDirectMusicComposer interface can be grouped as follows:
| Changing chords | ChangeChordMap |
| Composing segments | ComposeSegmentFromShape |
| ComposeSegmentFromTemplate | |
| Composing templates | ComposeTemplateFromShape |
| Composing transitions | AutoTransition |
| ComposeTransition |
All COM interfaces inherit the IUnknown interface methods. This interface supports the following three methods:
| IUnknown | AddRef |
| QueryInterface | |
| Release |
Windows NT/2000: Requires Windows 2000.
Windows 95/98: Requires Windows 95 or later. Available as a redistributable for Windows 95.
Header: Declared in dmusici.h.