DirectMusic™ is the musical component of the DirectX® application programming interface (API). Unlike the DirectSound® API, which is for the capture and playback of digital sound samples, DirectMusic works with message-based musical data which is converted to wave samples either in hardware or in a software synthesizer. The default software implementation uses the Microsoft® Software Synthesizer to create wave samples that are then streamed to DirectSound. Instrument voices are synthesized from samples according to the downloadable sounds (DLS) standard.
As well as supporting input in Musical Instrument Digital Interface (MIDI) format, DirectMusic can compose music at run time. This music is not algorithmically generated but is based on elements authored by a human composer. (The Microsoft authoring tool, DirectMusic Producer, is documented separately.) It is performed with variations and can respond dynamically to program events.
Like other components of DirectX, DirectMusic provides an API based on the Component Object Model (COM).
DirectMusic delivers full functionality on Windows® 95, Windows 98, and Windows 2000.