The EchoTool sample shows how to implement a tool in DirectMusic.
Source: (SDK root)\Samples\Multimedia\Dmusic\Src\EchoTool
Executable: (SDK root)\Samples\Multimedia\DMusic\Bin
Select an option button to change the delay of the echoes. Click the Close button to exit the application.
The tool creates up to four delayed echoes of the music playing through it.
Helper.cpp contains useful functions that set up DirectMusic. These functions are called from Main.cpp. Echotool.cpp contains the tool code.
For more information, see Tutorial 2: Using Tools.