Grace note

${ { \override Score.TimeSignature #'stencil = ##f \relative c'' { \time 2/4 \slashedGrace { d8( } c4) \slashedGrace { e8( } d4) } } }$

Acciaccatura notation

A grace note is a kind of music notation denoting several kinds of musical ornaments. It is usually printed smaller to indicate that it is melodically and harmonically nonessential. When occurring by itself, a single grace note indicates either an acciaccatura when notated with an oblique stroke through the stem, or an appoggiatura when notated without. When they occur in groups, grace notes can be interpreted to indicate any of several different classes of ornamentation, depending on interpretation. For percussion, such as drums, a related concept are ghost notes — supportive snare-hits at a lower volume.