Mensural notation recoverable from the modern text. While 19th and early 20th century editions of Renaissance music often preserved the large note values of the originals, including breves and longs, most modern editions will use scaled-down note values in order to match modern reading habits regarding tempo and beat structure. For 16th century music, a frequent scheme is diminution by a factor of 2 (i.e., rendering semibreves as modern minims), in a modern "alla breve" bar. Older music might be diminished by a factor of 4 (rendering semibreves as crotchets) or sometimes 8 (rendering breves as crotchets). For 13th-century pieces, diminution by
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