 Confusingly, the German "System" (often in the combined forms "Liniensystem" or "Notensystem") may refer to a single staff as well as to the "Akkolade" (from the French) or system in the English sense; the Italian term is "accollatura".When music on two staves is joined by a brace, or is intended to be played at once by a single performer (usually a keyboard instrument or harp), a grand staff (American English) or great stave (British English) is created.Typically, the upper staff uses a treble clef and the lower staff has a bass clef.