Reed division
Collective term for the reed stops (reed pipes) of an organ.
What it means
The term reed division (or reed stops) refers to the whole group of reed stops in an organ, that is, all stops whose tone is produced by a vibrating metal tongue inside a resonator, as opposed to flue stops, whose tone is produced solely by wind striking the pipe's edge.
Musical use
The reed division includes stops such as Trumpet, Trombone, Shawm (Schalmei) or Vox humana; they give the organ a sharper, overtone-rich sound and are often used for powerful solos or festive tutti registrations. The reed division is distinct from the flue division, which comprises all flute and principal stops, whose sound is softer and more fundamental, since it arises without a vibrating tongue, purely from the airstream at the pipe's edge.
Performance practice
Use reed stops deliberately when you want to give a registration sharpness and carrying power, and combine them with flue stops to round off the often edgy reed tone.