Hierarchy classification:

1. top of the aat hierarchies
2. Objects Facet
3. Furnishings and Equipment (hierarchy name)
4. Sound Devices (hierarchy name)
5. sound devices (equipment)
6. [sound devices by function]
7. tuning devices

Anotations

Scope note:

Wood pipes used to sound specific pitches, usually for singers. Some models are of pistonlike construction, with a calibrated plunger pushed in or pulled out to give various pitches; models without a plunger give a single standard pitch.