The term Sound refers to a patch, program, or preset provided by a Device. For an Instrument to be able to render music, it needs to be assigned a Sound. This is referred to as Sound Assignment.

A Sound cannot be physically accessed in Synfire. It is merely an address used to find and select a real sound connected via MIDI or hosted as audio plug-in, and then send MIDI data to it.

Sound vs. Instrument

While a Sound is a permanent part of a Device, an Instrument lives in an Arrangement, determining how to play a Sound. Multiple Instruments with different properties may use the very same Sound, such as in a counterpoint part where multiple voices move along in different ranges.