Instruments and Downloading

To play an instrument, the synthesizer needs information about how the instrument should sound. This information, consisting of wave samples and articulation data, is stored in DLS collections. Instrument data is made available to the synthesizer by being downloaded.

Typically a range of notes for one instrument is based on one sample that is appropriately pitched for each note. However, DLS Level 2 enables each note to be based on a different sample or combination of samples. Even the velocity of a note can trigger the use of different samples for that instrument.

By default, the Microsoft software synthesizer takes its DLS data from the Roland GM/GS collection. The default collection contains DLS data for the 128 instruments defined by the General MIDI standard. Custom collections can include instruments of any kind. The wave samples for an instrument do not have to be based on a musical instrument but can be any recorded sound such as a sound effect, a fragment of speech, or even a fully formed measure of music.

Most applications do not need to access collections directly, as the necessary data is either contained in the default collection or referenced by a band object associated with a segment. A band is a set of instruments and settings mapped to performance channels. Several techniques are available for ensuring that band instruments are downloaded before use.

Note   The Roland GM/GS Sound Set cannot be modified, due to legal restrictions.

Wave files and resources also have to be downloaded to the synthesizer before they can be played.