Assertion: piano's key | /r/DefinedAs | the number of flats
Facets:
Source sentences:
text: Different keys are defined by the number of flats in the key signature, starting with the leftmost, i.e., B ♭ , and proceeding to the right; for example, if only the first two flats are used, the key is B ♭ major/G minor, and all B's and E's are "flatted" (US) or "flattened" (UK), i.e., lowered to B ♭ and E ♭ .