Ingmar Krause had a question about "doorloop" today. Doorloop has
nothing to do with doors, nor with loops. It is best translated with
"run-through".  Originally, a "doorloop" is a piece of organ-book with
all notes of the organ in order of pitch, from bass to melody. The
counter-melody, when present, is a separate piece of the same book. A
"doorloop" is used to test if all keys are functioning properly.
Sometimes it is combined with the "stemboek", a special book with
fifths and octaves that is used for tuning purposes.  The name
"doorloop" (say: door-loup) has been erratically used for a simple scale
stick.

Hans van Oost, KDV, Netherlands