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 acoustical characteristics]
7. electrophones
8. electronic instruments

Additional parents:

1. top of the aat hierarchies
2. Objects Facet
3. Furnishings and Equipment
4. Sound Devices
5. sound devices
6. sound devices by function
7. musical instruments
8. keyboard instruments

Anotations

Scope note:

Electronic percussion instruments developed in the 1930s, involving a series of rotating wheels that interrupt beams of light to produce complex rhythms very precisely, controlled from a keyboard.