QuickTime Music Architecture

Music Components Included in QuickTime

Individual music components act as device drivers for each type of synthesizer attached to a particular computer. Three music components are included in QuickTime:

the QuickTime music synthesizer component, for playing music out of a computer's built-in speaker
the General MIDI synthesizer component, for playing music on a General MIDI device attached to a serial port.
the MIDI synthesizer component, which allows QuickTime to control a synthesizer that is connected to a single MIDI channel.

Developers can add other music components for specific hardware and software synthesizers. To better understand the role of a music component, see "The QuickTime Music Synthesizer Component" .

Applications do not usually call music components directly. Instead, the note allocator or tune player handles music component interactions. Music components are mainly of interest to application developers who want to access the low-level functionality of synthesizers and for developers of synthesizers (internal cards, MIDI devices, or software algorithms) who want to make the capabilities of their synthesizers available to QuickTime.

In order for an application to call a music component directly, you must first allocate a note channel and then use NAGetNoteChannelInfo and NAGetRegisteredMusicDevice to get the specific music component and part number.

You can use music component functions to

obtain specific information about a synthesizer
find an instrument that best fits a requested type of sound
play a note with a specified pitch and volume
change knob values to alter instrument sounds

Other functions are for handling instruments and synthesizer parts. You can use these functions to initialize a part to a specified instrument and to get lists of available instrument and drum kit names. You can also get detailed information about each instrument from the synthesizer and get information about and set knobs and controllers.