In DirectX for Visual Basic, music parameters are set and retrieved by using various methods of DirectMusicPerformance and DirectMusicSegment.

To have the music respond immediately to a changed parameter, an application can flush messages from the queue by using the DirectMusicPerformance.Invalidate method. This method causes all tracks to resend messages from the specified point forward.

DirectMusic lets you control many aspects of track behavior by changing parameters during execution, using one of the following SetParam methods:

• IDirectMusicPerformance::SetParam sets data on a specific track within the current control segment of this performance. The control segment is normally the primary segment, but a secondary segment can be designated as the control segment when it is played. See DMUS_SEGF_FLAGS.
• IDirectMusicSegment::SetParam sets data on a specific track within this segment.
• IDirectMusicTrack::SetParam sets data on this track.

In addition, the IDirectMusicPerformance::SetGlobalParam method allows you to set values that apply across the entire performance.

The equivalent GetParam and GetGlobalParam methods retrieve current values for a track or the performance.

To have the music respond immediately to a changed parameter, an application can flush messages from the queue by using the IDirectMusicPerformance::Invalidate method. This method causes all tracks to resend messages from the specified point forward.

More information about parameters is contained in the following topics:

• Setting and Retrieving Track Parameters
• Setting and Retrieving Global Parameters