Using Bands

A band is a choice of instruments assigned to particular parts in a style. At performance time, each instrument track is mapped to a PChannel, which stores the following information:

• MIDI volume.
• MIDI pan.
• Transposition. If this value is nonzero, music notes on the channel are automatically transposed for the instrument.
• The instrument's MIDI patch number, including MSB and LSB bank selects.
• A reference to the DLS collection from which to load the instrument. Optionally, the referenced DLS collection is the standard General MIDI collection.

Segments and styles always contain at least one band, called the default band. Styles can contain additional bands. When you load a segment or style, the default band and any other bands are automatically loaded as well. However, you still need to download the DLS data for the instruments in any band you intend to use. You can retrieve a pointer to the default band by using the IDirectMusicStyle::GetDefaultBand method.

Other bands might be authored into the style and can be found and retrieved by using the IDirectMusicStyle::EnumBand and IDirectMusicStyle::GetBand methods. Bands can also be obtained from other style files or from band files. Once you have obtained an IDirectMusicBand interface, you have access to that band and can substitute it for the default band.

Loading a band from its own file is just like loading any other object in DirectMusic. For more information, see Loading Objects.

More information about bands is contained in the following topics:

• Downloading and Unloading Bands
• Making Band Changes Programmatically
• Ensuring Timely Band Changes