Patch

A synthesizer patch (some manufacturers chose the term program) is a combination of settings and connections.

In modular synthesizers
Modular synthesizers use patch cordss to connect the different sound modules together. Since these machines had no memory to save settings, musicians wrote down the locations of the patch cords and knob positions on a "patch sheet", which usually showed a diagram of the synthesizer. Ever since, an overall sound setting for any type of synthesizer has been known as a patch.

In the late 1970s, patch memory (allowing storage and loading of "patches" or "programs") began to appear in synths like the Oberheim Four-voice, Sequential Circuits' Model 700 Programmer (1977) and Prophet-5 (1977/1978). After MIDI was introduced in 1983, more and more synthesizers could import or export patches via MIDI SysEx commands. When a synthesizer patch is uploaded to a personal computer that has patch editing software installed, the user can alter the parameters of the patch and download it back to the synthesizer. Because there is no standard patch language it is rare that a patch generated on one synthesizer can be used on a different model. However sometimes manufacturers design a family of synthesizers to be compatible.