Assertion: piano's mechanism | /r/HasProperty | developed
Facets:
value: by the 17th century
type: TEMPORAL
value: well
type: DEGREE
Source sentences:
text: By the 17th century, the mechanisms of keyboard instruments such as the clavichord and the harpsichord were well developed.
text: By the 17th century, the mechanisms of keyboard instruments such as the clavichord and the harpsichord were well developed.