Whole note they may occasionally be put under a different line (or ledger line) in more complicated polyphonic passages, or when two instruments or vocalists are written on one staff and one is temporarily silent. The whole note and whole rest may also be used in music of free rhythm, such as Anglican chant, to denote a whole measure, irrespective of the time of that measure. The whole rest can be used this way in almost all or all forms of music. The symbol is first found in music notation from the late thirteenth century . The whole note derives from the
Clavier-Übung III we trust, Protect Christ's congregation, His everlasting truth assert, All evil graciously avert, Lead us to life eternal.</poem> BWV 675, 66 bars long, is a two-part invention for the upper and lower voices with the "cantus firmus" in the alto part. The two outer parts are intricate and rhythmically complex with wide leaps, contrasting with the "cantus firmus" which moves smoothly by steps in minims and crotchets. The time signature has been taken to be one of the references in this movement to the Trinity. Like the two preceding chorale preludes, there is no explicit "manualiter" marking, only an ambiguous