Assertion: concertina's note | /r/HasProperty | one
Facets:
Source sentences:
text: A three-row model has an extra row of sharps and flats (accidentals) plus some redundant notes (that is, ones that duplicate those in the other two rows), allowing the instrument to be played in almost any given key.
text: The left side of the concertina is the bass side, and the lower notes are the ones that make up the top row.