Configuring Your Sound Card and MIDI Equipment > Procedures for Advanced MIDI Configuration Tasks > Installing a Software Synthesizer or Sound Library

A software synthesizer is a MIDI device driver that produces sound using your computer, as opposed to using specialized sound-creation circuitry in a sound card or external device. Sound cards that are pre-installed on computers and sound cards that you can purchase and install yourself usually include multiple MIDI device drivers. Some of these MIDI device drivers are for the sound card's internal sound-creation circuitry. One or more software synthesizers, provided as additional MIDI device drivers, might be included with the sound card.

Software synthesizers are also available as software products that can be purchased, or in some cases freely downloaded from the Internet, independently of which sound card you have.

After you install a software synthesizer, Composer will automatically detect it as a new Windows MIDI output port the next time you run the program. The software synthesizer will automatically become available as a new device.

Some sound libraries or synthesizers which are installed on your computer need a way to connect to Composer in order to be detected as a MIDI output device. There are a number of such "virtual cable" products available. The Windows MIDI Services, which is part of Windows 11 (version 25H2 OS build 26200.7700 and later) incorporates the capability of creating "loop backs" which act as connections for such internal devices. Your computer may or may not have the new Windows Musician Service available on it - please see the section in this documentation about MIDI Protocol Selection for further details.

Many software synthesizers have a built-in delay between the time a software program (such as Composer) requests a note to be played, and the time that the sound is actually produced. This requires special attention on your part. See the next topic, Adjusting for the Delay of Some MIDI Output Devices.

For sound libraries that you may use for your instrument sounds, you will need to refer to the Users Manual for those libraries to see how to set up each instrument for the device and channel, and then enter those values in the Staff Setup of Composer.