Common Music Notation (CMN) repertoire component declarations.
grace(optional)Marks a note or chord as a "grace" (without a definite performed duration) and records
from which other note/chord it should "steal" time.
Value conforms to data.GRACE.
grace.time(optional)Records the amount of time to be "stolen" from a non-grace note/chord.
Value conforms to data.PERCENT.