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. chordophones
8. zitherlike chordophones
9. zitherlike chordophones: struck
10. pianos

Anotations

Scope note:

Pianos whose individual notes have been changed in terms of timbre, pitch, and dynamics by means of placing various objects, such as rubber erasers, screws, bolts, and short sticks, at particular points between or on top of the strings. The idea came from American composer Henry Cowell, though the first prepared piano was created by American Minimal composer John Cage around 1940.