Note value Note value In music notation, a note value indicates the relative duration of a note, using the texture or shape of the "note head", the presence or absence of a "stem", and the presence or absence of "flags/beams/hooks/tails". Unmodified note values are fractional powers of two, for example one, one-half, one fourth, etc. A rest indicates a silence of an equivalent duration. The breve appears in several different versions, as shown at right. The first two are commonly used; the third is a stylistic alternative. Sometimes the longa or breve is used to indicate a very long note of indefinite
Grace note such time as audio recording was implemented, and even then, only a composer's personal or sanctioned recording could directly document usage. As either an appoggiatura or an acciaccatura, grace notes occur as notes of short duration before the sounding of the relatively longer-lasting note which immediately follows them. This longer note, to which any grace notes can be considered harmonically and melodically subservient (except in the cases of certain appoggiaturas, in which the ornament may be held for a longer duration than the note it ornaments), is called the "principal" in relation to the grace notes. A Grace note or