grace note

noun2

1. •
   A musical note, indicated on a score in smaller type with or without a slash through it, played to ornament the melody rather than as part of it. Its note value does not count as part of the total time value of the measure it appears in.
2. •
   (figurative) Something that decorates, embellishes, or ornaments; a finishing touch.

   • These concerns, often given mythic expression, explore the common human element in diverse experience: the poet [Rita Dove] touches the grace notes of famous and unknown lives, past and present. — 2006